No one will ever guess that the key ingredient to the buttery topping of this fresh, fruit-filled dessert is a pineapple cake mix. Select a cored pineapple with a generous amount of juice in the container to use in the batter.
Drain pineapple, reserving 3 tablespoons juice. Chop pineapple to measure 3 cups.
Combine chopped pineapple, reserved juice, and peach slices in an 11 x 7inch baking dish coated with cooking spray. Stir butter into cake mix until smooth. Spread batter over fruit; coat with cooking spray.
Bake at 350° for 38 minutes or until golden and bubbly. Serve warm with frozen yogurt. Sprinkle each serving with 1 tablespoon pecans, if desired.