In a medium sized bowl, toss apples with ½ cup sugar, cinnamon, and water. Transfer the apple mixture to an 8×8 pan sprayed with cooking spray.
In large bowl, add the flour, oats, sugar, baking powder, baking soda, and salt. Stir to combine . Pour the melted butter over the flour mixture and stir until the flour is moist.
Crumble the topping with fingers over top of sliced apples until apples are entirely covered.
Bake 35 minutes, or until top is golden brown and filling is bubbling up through the sides of the crisp.
Serve warm with a scoop of vanilla ice cream or topping of your choice.