For the frosting:
- 2 sticks unsalted butter, at room temperature
- Pinch of salt
- 3 cups confectioners' sugar
- 1 tablespoon vanilla extract
- 1 to 2 tablespoons milk
For the cake:
- Basic Vanilla Cake, baked and cooled
- Sprinkles, for decorating
Make the frosting: Beat the butter and salt in a large bowl with a mixer on medium speed until smooth and fluffy, 1 to 2 minutes. Gradually beat in the confectioners' sugar until smooth. Add the vanilla, increase the mixer speed to medium high and beat until thick, about 2 more minutes. Add the milk a little at a time and beat until the frosting is spreadable but not runny.
Assemble the cake: Put 1 cake layer on a platter; spread 1 cup frosting on top. Top with the second cake layer, then cover the whole cake with the remaining frosting. Decorate with sprinkles.
Photograph by Levi Brown