Preheat oven to 375 degrees F.

Crumble Toppings: In a medium size bowl combine oats, flour, brown sugar, cinnamon, and baking powder. Add butter and cut in with a pastry blender or fork until well combined. Refrigerate while you prepare the apple filling.

Apple Filling: (I use a Johnny Apple Peeler to peel, core and slice the apples all at once.) In a small bowl stir together melted butter and flour until smooth. Add lemon juice, milk and vanilla and stir. Stir in brown sugar, cinnamon, and nutmeg. Pour butter mixture over apples and toss to coat.

Bake: Pour apple mixture into an 8x8-inch baking dish and spread into an even layer. Sprinkle crumble topping evenly over the apples. Bake for about 35 minutes or until golden brown and top is set. Remove from oven cool at least 15 minutes before serving.

Serve with vanilla ice cream and homemade caramel sauce, if desired.