Step 1: Preheat your oven to 350F. Put the apples into a 2.5 litre (or 2.5 quart) casserole dish and add the apple layer ingredients. Toss the well until the apples are evenly coated, and press everything down into one layer.
Step 2: In a separate bowl, stir together the crumble ingredients until mixed well. They should have a texture similar to wet sand.
Step 3: Pour the crumble onto the apples and spread it, so the apples are evenly coated.
Step 4: Bake the crumble uncovered for 35-40 minutes. Remove the dish from the oven and cover it with a lid or foil and let it cool for 5-10 minutes