For cake, place water and Krusteaz Professional Angel Food Cake Mix in mixer bowl. (Be sure bowl and utensils are completely grease-free. Do not use plastic bowl.)
Using a whip, blend on low speed 1 minute. Scrape bowl. Change to medium speed and mix 2 minutes. Do not overmix.
Scale batter into ungreased 13 x 9 x 2 inch pan. Gently cut through batter with knife or spatula to remove large air bubbles.
For convection oven, bake at 325°F 20-25 minutes; for standard oven, bake at 350°F 30-35 minutes or until golden. Immediately invert onto glasses at either end of pan until completely cool (about 1 1/2 hours).
For filling, place ingredients in mixer bowl. Using a paddle, mix on low speed 2 minutes or until thickened. Chill until ready to use.
Remove cake from pan; tear or cut into 1-inch pieces.
Layer half of cake pieces into 13 x 9 x 2-inch pan. Spread half of filling over cake pieces. Repeat with remaining cake and filling. Serve with whipped cream and spun sugar, if desired.