FOOLPROOF SPONGE CAKE(COOK'S ILLUSTRATED)

Steps:

• Adjust oven rack to lower middle position and heat oven to 350 degrees. Grease two 8- or 9-inch cake pans and cover pan bottoms with a round of parchment paper. Whisk flours, baking powder, and salt in a medium bowl (or sift onto waxed paper). Heat milk and butter in a small saucepan over low heat until butter melts. Remove from heat and add vanilla; cover and keep warm.
• Separate three of the eggs, placing whites in bowl of standing mixer fitted with whisk attachment (or large mixing bowl if using hand mixer or whisk) and reserving the 3 yolks plus remaining 2 whole eggs in another mixing bowl. Beat the 3 whites on high speed (or whisk) until whites are foamy. Gradually add 6 tablespoons of the sugar; continue to beat whites to soft, moist peaks. (Do not over-beat.) If using a standing mixer, transfer egg whites to a large bowl and add yolk/whole egg mixture to mixing bowl.
• Beat the 3 yolks & 2 whole egg mixture with remaining 6 tablespoons sugar. Beat on medium-high speed (setting 8 on a KitchenAid) until eggs are very thick and a pale yellow color, about 5 minutes (or 12 minutes by hand). Add beaten eggs to whites.
• Sprinkle flour mixture over beaten eggs and whites; fold very gently 12 times with a large rubber spatula. Make a well in one side of batter and pour milk mixture into bowl. Continue folding until batter shows no trace of flour, and whites and whole eggs are evenly mixed, about 8 additional strokes.
• Immediately pour batter into prepared baking pans; bake until cake tops are light brown and feel firm and spring back when touched, about 16 minutes for 9-inch cake pans and 20 minutes for 8-inch cake pans.
• Immediately run a knife around pan perimeter to loosen cake. Cover pan with large plate. Using a towel, invert pan and remove pan from cake. Peel off parchment. Re-invert cake from plate onto rack, (see illustrations below). Repeat with remaining cake and continue with one of the related recipes.
• Step-by-Step Folding Without Deflating: With spatula perpendicular to the batter, cut through the center down to the bottom of the bowl.
• Holding the spatula blade flat against the bowl, scoop along bottom, then slide up the side of the bowl.
• Fold over, lifting the spatula high so that the batter falls without the spatula pressing down the batter.