Chop up enough apples to fill a 8x12 baking dish. Mix in 1/2 cup sugar, 1 T flour, and 1 tsp cinnamon. You can add some lime juice too, if you like.
In a separate bowl combine 1/4 cup brown sugar, 1 1/2 cups oats, 1/4 cup butter, and 6 T flour. Sprinkle that on top of the apples and bake at 190/375 for 30-40 minutes.