Adding instant pudding to the batter for cakes and cupcakes, such as these, has long been a way to ensure that they remain wonderfully moist after baking (even by recipes from box cake mixes). This recipe takes that step even further by using instant pudding mix for the "frosting" as well. You can use pretty much any flavor of instant pudding for both batter and topping, but vanilla or chocolate are always safe bets and guaranteed crowdpleasers, especially among the younger set.