Preheat the oven to 400°F.
Peel, core, and slice the apples. Mix the sugar, cinnamon, and flour and add to apples. Stir to mix and let sit for 10-15 minutes.
Mix oatmeal, brown sugar, flour, cinnamon, and salt. Melt butter and peanut butter and stir to blend. Add to dry ingredients and blend thoroughly.
Pile the apples in the pic crust, heaping them higher in the middle. Spread the topping evenly over. Bake for 35-45 minutes. Apples should be bubbling and topping lightly browned.