Apple Dump Cake

1 box vanilla cake mix
2 (21 oz) cans apple pie filling
1/2 cup butter (one stick), cut into 1/2 Tbsp slices
Optional Topping
1 cup rolled oats
1/2 cup brown sugar 

Preheat oven to 350°
Spray a 9x13 baking dish with cooking spray
Pour both cans of apple pie filling into the bottom of the dish
Spread the dry cake mix on top of the apple pie filling
Evenly place the butter on top of the cake mix

(Optional Topping) In a bowl combine the oats and the brown sugar and sprinkle that on top of the whole cake
Bake for approx 50 minutes, golden and bubbly.
Cool on wire rack.

Serve warm with vanilla ice cream
(Butter Pecan)