Already made this twice and doubled the recipe both times using a 9x13 pan. Used only approx 3/4 c. of pure maple syrup for a doubled recipe. Mixed apples with cinnamon and nutmeg and 2T. of flour. Sliced apples right in pan and mixed altogether with syrup, spices and flour. Also doubled topping but cut back on butter, used only about 1 1/2 sticks (12T.) and mixed as for pie crust in my food processor, then added the b. sugar and rolled oats (the only kind I use at home) along with more cinnamon, nutmeg and a little salt. Baked for 40 minutes at 375 F. Used Empire and Cortland Apples. Thank you, to all those good cooks out there, I read the reviews before I made this and it turned out Wonderful!