1. Preheat the oven to 350 degrees F.
2. Apple Mixture: Mix together all apple mixture ingredients (apples, sugar, flour, and cinnamon) and pour into a greased 9"x13" baking dish or pan.
3. Crumb Topping: Mix together all the crumb topping ingredients (brown sugar, butter, flour, oatmeal, and salt) until crumbly. If it seems too gooey, either add a more brown sugar and oats or don't put in as much butter.
4. Bake for 50 to 60 minutes. (This recipe freezes great before baking, just be sure to bake a little longer.)
Source: My Grandmother gave me this recipe and I veganized it, but the crumb mixture seemed very gooey just by following the recipe so I added some oats and brown sugar. It was a little hard to crumble, but the end result was beautiful!