From Tosi: My favorite offering at Milk Bar is our cake truffles, spawned entirely from leftover bits and pieces of cake! You can choose to follow the recipe, or get crazy, without our guidance, using leftovers to concoct your own. Don’t limit yourself to birthday cake; you can use any cake scrap and any leftover fillings, crumbs, or crunches from your kitchen!
YIELDS: Makes about one dozen 1-ounce cake truffles
Birthday Cake Base
Birthday Cake Base
Heat the oven to 350°f.
Combine the butter, shortening, and sugars in the bowl of a stand mixer fitted with the paddle attachment and cream together on medium-high for 2 to 3 minutes. Scrape down the sides of the bowl, add the eggs, and mix on medium-high for 2 to 3 minutes. scrape down the sides of the bowl once more.
On low speed, stream in the buttermilk, oil, and vanilla. increase the mixer speed to medium-high and paddle for 4 to 6 minutes, until the mixture is practically white, twice the size of your original fluffy butter-and-sugar mixture, and completely homogeneous. don’t rush the process. You’re basically forcing too much liquid into an already fatty mixture that doesn’t want to make room for that liquid. There should be no streaks of fat or liquid. Stop the mixer and scrape down the sides of the bowl.
On very low speed, add the cake flour, baking powder, salt, and the 50 g (¼ cup) rainbow sprinkles. Mix for 45 to 60 seconds, just until your batter comes together. Scrape down the sides of the bowl.
Pam-spray a quarter sheet pan and line it with parchment, or just line the pan with a silpat. Using a spatula, spread the cake batter in an even layer in the pan. Sprinkle the remaining 25g (2 tablespoons) rainbow sprinkles evenly on top of the batter.
Bake the cake for 30 to 35 minutes. The cake will rise and puff, doubling in size, but will remain slightly buttery and dense. At 30 minutes, gently poke the edge of the cake with your finger: the cake should bounce back slightly and the center should no longer be jiggly. Leave the cake in the oven for an extra 3 to 5 minutes if it doesn't pass these tests.
Take the cake out of the oven and cool on a wire rack or, in a pinch, in the fridge or freezer (don't worry, it's not cheating). The cooled cake can be stored in the fridge, wrapped in plastic wrap, for up to 4 days.