diff --git a/msbuild/Xamarin.Mac.Tasks/Xamarin.Mac.Common.targets b/msbuild/Xamarin.Mac.Tasks/Xamarin.Mac.Common.targets
index 86229f5e0b..1ce80d8708 100644
--- a/msbuild/Xamarin.Mac.Tasks/Xamarin.Mac.Common.targets
+++ b/msbuild/Xamarin.Mac.Tasks/Xamarin.Mac.Common.targets
@@ -27,8 +27,10 @@ Copyright (C) 2014 Xamarin. All rights reserved.
 	<UsingTask TaskName="Xamarin.MacDev.Tasks.FindItemWithLogicalName" AssemblyFile="Xamarin.Mac.Tasks.dll" />
 	<UsingTask TaskName="Xamarin.MacDev.Tasks.PackLibraryResources" AssemblyFile="Xamarin.Mac.Tasks.dll" />
 	<UsingTask TaskName="Xamarin.MacDev.Tasks.PropertyListEditor" AssemblyFile="Xamarin.Mac.Tasks.dll" />
+	<UsingTask TaskName="Xamarin.MacDev.Tasks.ReadItemsFromFile" AssemblyFile="Xamarin.Mac.Tasks.dll" />
 	<UsingTask TaskName="Xamarin.MacDev.Tasks.SmartCopy" AssemblyFile="Xamarin.Mac.Tasks.dll" />
 	<UsingTask TaskName="Xamarin.MacDev.Tasks.UnpackLibraryResources" AssemblyFile="Xamarin.Mac.Tasks.dll" />
+	<UsingTask TaskName="Xamarin.MacDev.Tasks.WriteItemsToFile" AssemblyFile="Xamarin.Mac.Tasks.dll" />
 	<UsingTask TaskName="Xamarin.Mac.Tasks.ACTool" AssemblyFile="Xamarin.Mac.Tasks.dll" />
 	<UsingTask TaskName="Xamarin.Mac.Tasks.CodesignVerify" AssemblyFile="Xamarin.Mac.Tasks.dll" />
 	<UsingTask TaskName="Xamarin.Mac.Tasks.CompileAppManifest" AssemblyFile="Xamarin.Mac.Tasks.dll" />
@@ -73,6 +75,12 @@ Copyright (C) 2014 Xamarin. All rights reserved.
 		<_PreparedResourceRules></_PreparedResourceRules>
 		<_AppBundleName>$(AssemblyName)</_AppBundleName>
 	</PropertyGroup>
+		
+	<PropertyGroup>
+		<!-- actool output caches -->
+		<_ACTool_PartialAppManifestCache>$(IntermediateOutputPath)actool\_PartialAppManifest.items</_ACTool_PartialAppManifestCache>
+		<_ACTool_BundleResourceCache>$(IntermediateOutputPath)actool\_BundleResourceWithLogicalName.items</_ACTool_BundleResourceCache>
+	</PropertyGroup>
 
 	<Import Project="$(MSBuildThisFileDirectory)Xamarin.Mac.Common.ImplicitFacade.xbuild.targets"
 		Condition="'$(IsXBuild)' == 'true' "/>
@@ -558,12 +566,40 @@ Copyright (C) 2014 Xamarin. All rights reserved.
 		</CreateItem>
 	</Target>
 
-	<Target Name="_CompileImageAssets" DependsOnTargets="_DetectAppManifest;_DetectSdkLocations;_CoreCompileImageAssets" />
+	<Target Name="_CompileImageAssets" DependsOnTargets="_DetectAppManifest;_DetectSdkLocations;_BeforeCoreCompileImageAssets;_ReadCompileImageAssets;_CoreCompileImageAssets" />
+
+	<Target Name="_BeforeCoreCompileImageAssets"
+		Inputs="@(ImageAsset);$(_AppManifest)"
+		Outputs="$(_ACTool_PartialAppManifestCache);$(_ACTool_BundleResourceCache)">
+		
+		<!-- If any ImageAsset or AppManifest is newer than the generated items list, we delete them so that the _CoreCompileImageAssets
+		     target runs again and updates those lists for the next run
+		-->
+		<Delete Files="$(_ACTool_PartialAppManifestCache);$(_ACTool_BundleResourceCache)" />
+		<RemoveDir Directories="$(IntermediateOutputPath)actool" />
+	</Target>
+
+	<Target Name="_ReadCompileImageAssets"					
+		DependsOnTargets="_BeforeCoreCompileImageAssets">
+
+		<!-- If _BeforeCoreCompileImageAssets did not delete the generated items lists from _CoreCompileImageAsset, then we read them
+		     since that target won't run and we need the output items that are cached in those files, which includes full metadata -->
+		<ReadItemsFromFile File="$(_ACTool_PartialAppManifestCache)" Condition="Exists('$(_ACTool_PartialAppManifestCache)')">
+			<Output TaskParameter="Items" ItemName="_PartialAppManifest" />
+		</ReadItemsFromFile>
+		<ReadItemsFromFile File="$(_ACTool_BundleResourceCache)" Condition="Exists('$(_ACTool_BundleResourceCache)')">
+			<Output TaskParameter="Items" ItemName="_BundleResourceWithLogicalName" />
+		</ReadItemsFromFile>
+	</Target>
+
+	<Target Name="_CoreCompileImageAssets"
+		Inputs="@(ImageAsset);$(_AppManifest)"
+		Outputs="$(_ACTool_PartialAppManifestCache);$(_ACTool_BundleResourceCache)"
+		DependsOnTargets="_DetectAppManifest;_DetectSdkLocations;_BeforeCoreCompileImageAssets">
 
-	<Target Name="_CoreCompileImageAssets">
 		<ACTool
-			Condition="'$(IsMacEnabled)' == 'true'"
 			SessionId="$(BuildSessionId)"
+			Condition="'$(IsMacEnabled)' == 'true' And '@(ImageAsset)' != ''"
 			ToolExe="$(ACToolExe)"
 			ToolPath="$(ACToolPath)"
 			AppManifest="$(_AppManifest)"
@@ -574,17 +610,26 @@ Copyright (C) 2014 Xamarin. All rights reserved.
 			IntermediateOutputPath="$(IntermediateOutputPath)"
 			ProjectDir="$(MSBuildProjectDirectory)"
 			ResourcePrefix="$(XamMacResourcePrefix)"
-			SdkPlatform="MacOSX"
+
 			SdkDevPath="$(_SdkDevPath)"
 			SdkBinPath="$(_SdkBinPath)"
 			SdkUsrPath="$(_SdkUsrPath)"
+			SdkPlatform="MacOSX"
 			SdkVersion="$(MacOSXSdkVersion)">
-			<Output TaskParameter="PartialAppManifest" ItemName="FileWrites" />
-			<Output TaskParameter="OutputManifests" ItemName="FileWrites" />
-			<Output TaskParameter="BundleResources" ItemName="FileWrites" />
 			<Output TaskParameter="PartialAppManifest" ItemName="_PartialAppManifest" />
 			<Output TaskParameter="BundleResources" ItemName="_BundleResourceWithLogicalName" />
+
+			<!-- Local items to be persisted to items files -->
+			<Output TaskParameter="PartialAppManifest" ItemName="_ACTool_PartialAppManifest" />
+			<Output TaskParameter="BundleResources" ItemName="_ACTool_BundleResources" />
 		</ACTool>
+		
+		<!-- Cache the generated outputs items for incremental build support -->
+		<WriteItemsToFile Items="@(_ACTool_PartialAppManifest)" ItemName="_PartialAppManifest" File="$(_ACTool_PartialAppManifestCache)" Overwrite="true" IncludeMetadata="true" />
+		<WriteItemsToFile Items="@(_ACTool_BundleResources)" ItemName="_BundleResourceWithLogicalName" File="$(_ACTool_BundleResourceCache)" Overwrite="true" IncludeMetadata="true" />
+		<ItemGroup>
+			<FileWrites Include="$(_ACTool_PartialAppManifestCache);$(_ACTool_BundleResourceCache)" />
+		</ItemGroup>
 	</Target>
 
 	<Target Name="_CompileSceneKitAssets" DependsOnTargets="_DetectAppManifest;_DetectSdkLocations;_CoreCompileSceneKitAssets" />
diff --git a/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-128.png b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-128.png
new file mode 100644
index 0000000000..d0b5a8098e
Binary files /dev/null and b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-128.png differ
diff --git a/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-128@2x.png b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-128@2x.png
new file mode 100644
index 0000000000..f4c8d29047
Binary files /dev/null and b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-128@2x.png differ
diff --git a/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-16.png b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-16.png
new file mode 100644
index 0000000000..ebb5a0fe4e
Binary files /dev/null and b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-16.png differ
diff --git a/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-16@2x.png b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-16@2x.png
new file mode 100644
index 0000000000..0986d31beb
Binary files /dev/null and b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-16@2x.png differ
diff --git a/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-256@2x.png b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-256@2x.png
new file mode 100644
index 0000000000..a142c83fb1
Binary files /dev/null and b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-256@2x.png differ
diff --git a/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-32.png b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-32.png
new file mode 100644
index 0000000000..0986d31beb
Binary files /dev/null and b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-32.png differ
diff --git a/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-32@2x.png b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-32@2x.png
new file mode 100644
index 0000000000..412d6ca9b4
Binary files /dev/null and b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/AppIcon-32@2x.png differ
diff --git a/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/Contents.json b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/Contents.json
new file mode 100644
index 0000000000..deda2078f0
--- /dev/null
+++ b/tests/common/mac/Icons/Assets.xcassets/AppIcon.appiconset/Contents.json
@@ -0,0 +1,238 @@
+{
+  "images": [
+    {
+      "size": "20x20",
+      "scale": "2x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "20x20",
+      "scale": "3x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "29x29",
+      "scale": "2x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "29x29",
+      "scale": "3x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "40x40",
+      "scale": "2x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "40x40",
+      "scale": "3x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "60x60",
+      "scale": "2x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "60x60",
+      "scale": "3x",
+      "idiom": "iphone"
+    },
+    {
+      "size": "20x20",
+      "scale": "1x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "20x20",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "29x29",
+      "scale": "1x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "29x29",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "40x40",
+      "scale": "1x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "40x40",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "83.5x83.5",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "76x76",
+      "scale": "1x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "76x76",
+      "scale": "2x",
+      "idiom": "ipad"
+    },
+    {
+      "size": "1024x1024",
+      "scale": "1x",
+      "idiom": "ios-marketing"
+    },
+    {
+      "size": "60x60",
+      "scale": "2x",
+      "idiom": "car"
+    },
+    {
+      "size": "60x60",
+      "scale": "3x",
+      "idiom": "car"
+    },
+    {
+      "role": "notificationCenter",
+      "size": "24x24",
+      "subtype": "38mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "notificationCenter",
+      "size": "27.5x27.5",
+      "subtype": "42mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "companionSettings",
+      "size": "29x29",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "companionSettings",
+      "size": "29x29",
+      "scale": "3x",
+      "idiom": "watch"
+    },
+    {
+      "role": "appLauncher",
+      "size": "40x40",
+      "subtype": "38mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "appLauncher",
+      "size": "44x44",
+      "subtype": "40mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "appLauncher",
+      "size": "50x50",
+      "subtype": "44mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "quickLook",
+      "size": "86x86",
+      "subtype": "38mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "quickLook",
+      "size": "98x98",
+      "subtype": "42mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "role": "quickLook",
+      "size": "108x108",
+      "subtype": "44mm",
+      "scale": "2x",
+      "idiom": "watch"
+    },
+    {
+      "size": "1024x1024",
+      "scale": "1x",
+      "idiom": "watch-marketing"
+    },
+    {
+      "filename": "AppIcon-16.png",
+      "size": "16x16",
+      "scale": "1x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "AppIcon-16@2x.png",
+      "size": "16x16",
+      "scale": "2x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "AppIcon-32.png",
+      "size": "32x32",
+      "scale": "1x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "AppIcon-32@2x.png",
+      "size": "32x32",
+      "scale": "2x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "AppIcon-128.png",
+      "size": "128x128",
+      "scale": "1x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "AppIcon-128@2x.png",
+      "size": "128x128",
+      "scale": "2x",
+      "idiom": "mac"
+    },
+    {
+      "size": "256x256",
+      "scale": "1x",
+      "idiom": "mac"
+    },
+    {
+      "filename": "AppIcon-256@2x.png",
+      "size": "256x256",
+      "scale": "2x",
+      "idiom": "mac"
+    },
+    {
+      "size": "512x512",
+      "scale": "1x",
+      "idiom": "mac"
+    },
+    {
+      "size": "512x512",
+      "scale": "2x",
+      "idiom": "mac"
+    }
+  ],
+  "info": {
+    "version": 1,
+    "author": "xcode"
+  }
+}
\ No newline at end of file
diff --git a/tests/common/mac/Icons/Assets.xcassets/Contents.json b/tests/common/mac/Icons/Assets.xcassets/Contents.json
new file mode 100644
index 0000000000..4caf392f92
--- /dev/null
+++ b/tests/common/mac/Icons/Assets.xcassets/Contents.json
@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "version" : 1,
+    "author" : "xcode"
+  }
+}
\ No newline at end of file
diff --git a/tests/common/mac/ProjectTestHelpers.cs b/tests/common/mac/ProjectTestHelpers.cs
index 92bf8d7e25..0911433013 100644
--- a/tests/common/mac/ProjectTestHelpers.cs
+++ b/tests/common/mac/ProjectTestHelpers.cs
@@ -161,6 +161,9 @@ namespace Xamarin.MMP.Tests
 			public string APIDefinitionConfig { get; set; }
 			public string StructsAndEnumsConfig { get; set; }
 
+			// Unified Executable Specific
+			public bool AssetIcons { get; set; }
+
 			// Generated by TestUnifiedExecutable/TestSystemMonoExecutable and added to TestCode
 			public Guid guid { get; set; }
 
@@ -306,6 +309,24 @@ namespace Xamarin.MMP.Tests
 
 			string sourceDir = FindSourceDirectory ();
 
+			if (config.AssetIcons) 
+			{
+				RunAndAssert ("/bin/cp", $"-R {Path.Combine (sourceDir, "Icons/Assets.xcassets")} {config.TmpDir}", "Copy Asset Icons");
+				config.ItemGroup += @"<ItemGroup>
+    <ImageAsset Include=""Assets.xcassets\AppIcon.appiconset\Contents.json"" />
+    <ImageAsset Include=""Assets.xcassets\AppIcon.appiconset\AppIcon-128.png"" />
+    <ImageAsset Include=""Assets.xcassets\AppIcon.appiconset\AppIcon-128%402x.png"" />
+    <ImageAsset Include=""Assets.xcassets\AppIcon.appiconset\AppIcon-16.png"" />
+    <ImageAsset Include=""Assets.xcassets\AppIcon.appiconset\AppIcon-16%402x.png"" />
+    <ImageAsset Include=""Assets.xcassets\AppIcon.appiconset\AppIcon-256%402x.png"" />
+    <ImageAsset Include=""Assets.xcassets\AppIcon.appiconset\AppIcon-32.png"" />
+    <ImageAsset Include=""Assets.xcassets\AppIcon.appiconset\AppIcon-32%402x.png"" />
+    <ImageAsset Include=""Assets.xcassets\Contents.json"" />
+  </ItemGroup>";
+				// HACK - Should process using CopyFileWithSubstitutions
+				config.PlistReplaceStrings.Add ("</dict>", @"<key>XSAppIconAssets</key><string>Assets.xcassets/AppIcon.appiconset</string></dict>");
+			}
+
 			CopyFileWithSubstitutions (Path.Combine (sourceDir, "Info-Unified.plist"), Path.Combine (config.TmpDir, "Info.plist"), text => {
 				foreach (var key in config.PlistReplaceStrings.Keys)
 					text = text.Replace (key, config.PlistReplaceStrings [key]);
diff --git a/tests/mmptest/src/MMPTest.cs b/tests/mmptest/src/MMPTest.cs
index 2784fa1457..f88af1830b 100644
--- a/tests/mmptest/src/MMPTest.cs
+++ b/tests/mmptest/src/MMPTest.cs
@@ -674,5 +674,28 @@ namespace Xamarin.MMP.Tests
 				rv.Messages.AssertWarningCount (0);
 			});
 		}
+
+		// [Test] - https://github.com/xamarin/xamarin-macios/issues/4110
+		public void BuildingSameSolutionTwice_ShouldNotRunACToolTwice ()
+		{
+			RunMMPTest (tmpDir => {
+				TI.UnifiedTestConfig test = new TI.UnifiedTestConfig (tmpDir) {
+					AssetIcons = true
+				};
+
+				string project = TI.GenerateUnifiedExecutableProject (test);
+
+				string buildOutput = TI.BuildProject (project, true, diagnosticMSBuild: true, useMSBuild: true);
+				Assert.True (buildOutput.Contains ("actool execution started with arguments"), $"Initial build should run actool");
+
+				buildOutput = TI.BuildProject (project, true, diagnosticMSBuild: true, useMSBuild: true);
+				Assert.False (buildOutput.Contains ("actool execution started with arguments"), $"Second build should not run actool");
+
+				TI.RunAndAssert ("touch", Path.Combine (tmpDir, "Assets.xcassets/AppIcon.appiconset/AppIcon-256@2x.png"), "touch icon");
+
+				buildOutput = TI.BuildProject (project, true, diagnosticMSBuild: true, useMSBuild: true);
+				Assert.True (buildOutput.Contains ("actool execution started with arguments"), $"Build after touching icon must run actool");
+			});
+		}
 	}
 }