Coat inside of 1 quart casserole with vegetable spray, spray well. Pour pie filling into casserole. Stir lemon juice into filling. Set aside. Whirl sugar, flour, cinnamon and butter in food processor until crumbly. Add oatmeal. Sprinkle over cherries. Bake in preheated oven, 375° for 25 minutes or until bubbly and browned on top. This good warm or cold. I can never leave well enough alone, so, I add sometimes, 1/4 cup raisins or nuts. The nuts need to be well chopped in small pieces, not into meal state though.