1 cup (2 sticks) unsalted butter, softened to room temperature
3 cups powdered sugar
2-3 tablespoons heavy cream or heavy whipping cream
1 teaspoon vanilla extract
pinch of salt
In the bowl of a stand mixer fitted with the paddle attachment, or in a large mixing bowl using an electric mixer, beat the butter on medium speed until smooth.
Add in the powdered sugar and mix on low speed at first, then increase to medium speed and continue mixing for another 1-2 minutes until the mixture starts to come together.
Add in the heavy cream (start with 2 tablespoons and add a little more if needed), vanilla extract, and salt and continue mixing on medium-high speed for another minute or until everything is well combined, scraping down the sides of the bowl as needed.
Turn it into Chocolate Frosting
Measure out 1/2 cup of unsweetened cocoa powder, sift it, then mix into the frosting until well combined. Add in 1-2 extra tablespoons of heavy cream if needed for a smoother, creamier frosting. If you prefer your frosting sweeter, mix in an additional 1/2 cup of powdered sugar.