To make sour milk, place 4 tsp. lemon juice or vinegar in a 2-cup glass measuring cup. Add enough milk to equal 1 cup total liquid; stir. Let stand 5 minutes before using.
Use any leftover batter to make cupcakes.
For extra stability, remove the ball cake from the cardboard piece and place on top of stacked layers. Press the straw in the ball cake all the way down into the layers underneath.
Use this delicious, easy-to-shape white chocolate candy clay as you would fondant.
Almost-Homemade Vanilla Buttercream
If only 13-oz. jars of marshmallow creme are available, purchase additional, then add 3 oz. (3/4 cup).