In a large bowl, combine the oats, brown sugar, baking powder, salt and cinnamon. Combine the eggs, milk and butter; add to the dry ingredients. Stir in the apple, peaches and blueberries.
Pour into an 8"-inch square baking dish coated with nonstick cooking spray. Bake, uncovered, at 350 for 35-40 minutes or until a knife inserted near the center comes out clean. Cut into squares. Serve with milk if desired.