Toss fruit, cinnamon and lemon juice together. Place in 8x11 baking dish.
Prepare batter by blending 3/4 cup sugar, butter, baking powder, flour and milk. Spoon batter over fruit layer. For topping, mix cornstarch with 3/4 cup sugar. Sprinkle over batter. Pour 1 cup boiling water over all. Bake 40-45 minutes at 350 degrees.