Step 1
Step 1Prepare the Cake: Preheat oven to 350°F. Grease a 13- x 9-inch pan with baking spray with flour. Place apple in a medium-size microwaveable bowl. Cover loosely with plastic wrap; microwave on HIGH until softened, about 4 minutes. Transfer apple and any liquid to a food processor or blender, and puree until smooth, 20 to 30 seconds. Let cool 10 minutes. (You should have 2 cups pureed apple.)

