Preheat oven to 325°F and set aside a cupcake pan filled with liners.
In a large bowl, whip mascarpone cheese and powdered sugar on medium-high speed, using a whisk attachment, until fluffy smooth, about 2 minutes.
Topping and frosting can be make ahead of time and kept refrigerated.
Mascarpone cheese provides structure to the whipped cream, and aids in keeping its shape. If mascarpone is not available, frost with regular whipped cream, but keep in mind that it might lose its shape and weep after some time.