1-Start by beating the butter on medium speed for 30 seconds until smooth. Add black cocoa powder, vanilla extract, and salt on low speed and mix well. Gradually incorporate the powdered sugar while mixing on low, then halfway through, pour in the heavy whipping cream to help with mixing.

2-Next, add the melted and cooled dark chocolate along with about 1 teaspoon of black gel food coloring. Beat the mixture on low speed until fully combined and the desired consistency is achieved. Adjust thickness by adding heavy cream a tablespoon at a time if too thick, or more powdered sugar in 1/4 cup increments if too thin. Finally, mix by hand with a rubber spatula to ensure even color and smooth texture. You can store it in sealed piping bags or an airtight container and let it rest at room temperature for a few hours or overnight to deepen the shade before refrigerating until ready to use.