Raspberry Lemon Cupcakes Ingredients Cupcakes: 2 1/4 cups cake flour 1 Tbsp baking powder 1/2 tsp kosher salt 1 1/4 cups buttermilk, room temperature 4 large egg whites, room temperature 1 1/2 cups sugar Fine zest from two lemon 1 stick (8 Tbsp) unsalted butter, room temperature 1 tsp pure vanilla extract 1/2 tsp