Use extra butter to grease an oven proof (serving) dish that holds roughly 2-3 quarts. [A 13x9 pan will also work.]
Peel and core apples. Cut into thick slices, place in a large bowl.
Combine sugar, cinnamon and flour. Sprinkle over cut up apples. Stir to coat apples with sugar mixture.
Pour the apples into your greased dish, layering them as necessary so that they all fit. [Keeping some gaps between the individual slices allows for the topping to seep into the filling while it cooks. This results in 'caramelized wonderfulness.']
Combine all of the dry topping ingredients together in a bowl.
Dice the butter into small cubes and add it to the dry topping mix.
Sprinkle the topping over the apples.
Bake for roughly 20 minutes 'until the apples are done' ...until the dish is bubbling hot.
Vegan and Dairy Free Adaption: Use vegan butter in place of dairy butter.