Step 1

Beat the butter for about 30 seconds, then mix in half the powdered sugar and mix until the sugar is moist.

Step 2

Add the mascarpone cheese and the rest of the sugar and mix until incorporated. Then, add the vanilla extract.

Step 3

Pour in the heavy cream and mix, starting with low speed and gradually increasing the speed to medium-high.

Step 4

Mix until the frosting has thickened and you have a light, smooth mixture. Do not overmix; otherwise, the mascarpone cheese will curdle.