Preheat oven to 375F and grease a 9x9 casserole dish with nonstick spray.
Prepare apples by peeling and dicing into chunks, then add to a large bowl.
Sprinkle apples with sugar, flour, cinnamon, nutmeg, salt, and lemon juice. Stir until all of the apples are completely coated. Pour into greased dish.
In a separate medium sized bowl, for the crumble, add flour, brown sugar, cinnamon, nutmeg, salt, baking powder. Mix together.
Add in melted butter and vanilla and stir until crumble forms.
Add the crumble topping to the apples, covering as much of it as you can.
Bake for 50-55 minutes or until crumble is golden brown and apples are bubbling.
Let cool for at least 30 minutes before serving! Serve with vanilla ice cream.