To make the cakes:

1. Preheat the oven (325 for dark pans and 350 for light pans). In a large bowl or the bowl of a stand mixer cream the butter and sugar together on medium speed until smooth and fluffy, about 2 minutes. Add the eggs one at a time, mixing after each addition to incorporate. Add the vanilla. Stir in the cake flour, baking powder, and salt just until combined and then fold in the sprinkles. Don’t agitate the sprinkles too much some varieties bleed their color.  Lightly grease mini muffin or cheesecake tins and fill each cup 2/3 of the way with batter. Bake in the preheated oven for about 15 minutes or until a toothpick inserted comes out clean. Allow to cool slightly in the pan and then carefully remove each cake to cool completely.

To prepare the filling:

1. In a large bowl, use a hand mixer to cream together the softened butter and cream cheese until smooth. Add the powdered sugar and heavy cream and whip on medium speed until fluffy, about 1 minutes. Fill a piping bag with the topping and pipe on top of each cake. Decorate with sprinkles as desired. Enjoy at a cool room temperature but store in the fridge.