Nonstick spray
5 cups all-purpose flour
4 cups cake flour
4 teaspoons baking powder
2 teaspoons baking soda
2 teaspoons fine salt
16 large egg whites, lightly beaten
4 cups sour cream
2 cups milk
6 tablespoons clear vanilla extract
Seeds from 2 vanilla beans
1 pound unsalted butter, softened
5 1/3 cups granulated sugar
1 pound fresh strawberries
1/2 cup granulated sugar
1/3 cup balsamic vinegar
2 tablespoons freshly-squeezed lemon juice
1 cup mascarpone cheese, room temperature
2 cups heavy cream
1/2 cup confectioners' sugar
1 tablespoon clear vanilla extract
1 pound unsalted butter, softened
2 cups shortening
2 pounds confectioners' sugar, sifted
4 teaspoons clear vanilla extract
None