Preheat the oven to 350 degrees. In a large mixing bowl add chopped apples, 1/4 cup brown sugar, water, vanilla, cinnamon, and sour cream. Mix until combined. In a medium saucepan add the apple mixture and cook over medium-high heat until the apples are softened. While apples are cooking grab a small bowl add oats, 2 tablespoons brown sugar, melted butter, a few more shakes of cinnamon, and a pinch of salt. Mix well. Spray a 3 quart casserole dish with cooking spray, add the cut up biscuit pieces and the top with the warmed apple pie filling. Lightly stir into the biscuits. Sprinkle the oat topping mix on top. Place into the oven for about 22 minutes or until the top is lightly browned and biscuits are bubbled up.