Preheat oven to 350°F.
Peel, core, and dice the apple. Divide chopped apples between two two-cup baking dishes.
Mix sugar and butter. Spoon sugar mixture over the apples.
Use a pastry blender to combine the topping ingredients. Crumble the topping over the apples.
Bake at 350° for 45 minutes. The sugar and butter will caramelize and form a rich, delicious top layer. Serve warm with whipped cream or vanilla ice cream.