Preheat oven to 350 degrees F.
Place the sliced apples in a 9×13 inch pan. For filling, mix the white sugar, flour and ground cinnamon together, and sprinkle over apples. Pour water evenly over all.
For topping, combine the Cinnamon Puffins, oats, flour, brown sugar, and melted butter together. Crumble evenly over the apple mixture.
Bake at 350 degrees F for about 45 minutes.Puffins Cinnamon