Servings: 10 people For the Apple Crisp Filling: 4 lbs firm-crisp apples, 11-12 medium apples 2 Tbsp lemon juice 3/4 cup granulated sugar, or to taste 3 Tbsp all-purpose flour 1 1/2 tsp cinnamon For the Crumb Topping: 1 3/4 cups flour 1/2 cup packed brown sugar 1/4 cup granulated sugar 1/2 tsp cinnamon 1/4 tsp salt 1 cup unsalted butter, or 16 Tbsp or 2 sticks (room temperature), plus more to butter pan 1 cup rolled oats, or old fashioned oats
Prep: Generously Butter a 9×13 casserole dish with 1/2 Tbsp butter. Preheat the oven to 375F.
Peel core and thinly slice apples to 1/4’ thickness. You should have 12 cups of sliced apples. Squeeze 2 Tbsp lemon juice over the apples and toss to coat.
In a separate bowl, stir together 3/4 cup sugar, 3 Tbsp flour, and 1 1/2 tsp cinnamon then sprinkle mixture over apples and toss to combine. Transfer apples into the buttered casserole dish.
Make the topping – in a large bowl, use your hands to stir together flour, oats, brown and granulated sugars, cinnamon, and salt. Add the diced butter and work it into the mixture with your hands until pea-sized crumbs form throughout. Spread topping over apples.
Bake at 375˚F for 45-50 minutes or until the topping is golden and crisp and apples are bubbling at the edges. The center should register above 175˚F.