Combine the apples, cherries, and ½ cup sugar or sweetener in an 8x8 dish.
Put 1 cup of oats, butter, and 3 tablespoon of sugar or sweetener in a food processor and pulse until crumbs form. Add the rest of the oats and pulse a few times until they are mixed in.
Top the apples and cherries with the oat topping.
Bake for 45-50 minutes until the apples have softened and the topping is browned.