Preheat oven to 400 degrees. Using a medium-sized spoon, mix all ingredients except the apples and butter in a large mixing bowl. Crush all lumps of brown sugar before adding butter. Place the stick of butter on top of mixture and set bowl in the heat of the warming oven. When the butter is nearly melted, stir it into the mixture (Barb likes to use a mixer; Bernie uses a medium-sized spoon). Fill a baking dish with prepared apples even with its top. Then add the prepared apples to the mixture in the mixing bowl; stir all ingredients together. Pour back into the baking dish, cover, and bake for 40 minutes.