1. Preheat oven to 350 degrees F.
2. Place the peaches and pineapple in an 8-inch by 8-inch baking dish.
3. Stir together the flour, sugar and cinnamon in a medium bowl. Cut in butter until mixture is crumbly and butter pieces are about the size of a pea. Sprinkle evenly over fruit.
4. Bake 30 minutes or until topping is crisp and golden. Serve warm with ice cream, if desired.