Place the second cake layer on top and use the rest of the frosting to cover the top and sides of the whole cake.
Mixture will be gritty and thin.
You can use any filling, but this dough is the star! We like the mini-me cupcake versions with a classic cream-cheese icing, or the gravity-defying triple-layer carrot cake by dessert queen Christina Tosi.
Some like me might even go so far as to call it extraordinary.