“Starting with the chocolate version, I swap out some of the cocoa powder with melted bittersweet chocolate and add some sour cream for balance and moistness, as well as some instant espresso powder, my secret ingredient for anything chocolate, which doesn't so much make something taste like coffee, but rather just makes chocolate taste more chocolaty. While the chocolate cupcakes are baking, I turn my attention to the vanilla recipe, adding some vanilla bean paste to amp up the vanilla flavor and show off those awesome little black-speck vanilla seeds, and mixing some buttermilk into the batter to prevent it from being overly sweet and unbalanced. The banana version uses very ripe bananas that I've been stashing in the freezer, as well as a single slice of fresh banana that has been coated in caramel and is pushed halfway into each cup of batter for a surprise in the middle of the cupcakes.
Herman's frostings are close to the frostings of my youth, simple faux buttercreams made with softened butter and confectioners' sugar. Nothing fancy. In my newer versions, the chocolate gets melted chocolate and chocolate milk mixed in, the vanilla gets more vanilla bean paste and a tiny hit of lemon zest, and the peanut butter gets a blend of butter and cream cheese for some tang.”