Take the butter, eggs, and milk out of the refrigerator about an hour before making the cake so they come to room temperature. Use this batter to make 24 standard cupcakes. Fill paper-lined or buttered and floured cupcake pans 2/3 full and bake for 20 to 25 minutes. Top with a half-batch of frosting. Pulsing the dry ingredients gives you a lighter cake. Cakes bake best in the center of the oven. Don't open the oven too often; you lose up to 70 degrees F each time. Press the center with your fingers to test doneness. If it bounces back, it's done; if it leaves a dent, keep baking. If the layers are uneven, use the thicker one on the bottom. This frosting keeps for a week in the fridge or a month in the freezer. Defrost in the refrigerator overnight or microwave gently until spreadable. When storing an already-cut cake, add half an apple to the cake box to keep the cake moist.