→ Apple Filling
01 - 6 medium apples (Granny Smith or Honeycrisp), peeled, cored, and sliced
02 - 1/4 cup granulated sugar
03 - 2 tablespoons all-purpose flour
04 - 1 teaspoon ground cinnamon
05 - 1/4 teaspoon ground nutmeg
06 - 1 tablespoon lemon juice
07 - Pinch of salt
→ Oat Topping
08 - 3/4 cup old-fashioned rolled oats
09 - 1/2 cup all-purpose flour
10 - 1/2 cup packed light brown sugar
11 - 1/2 teaspoon ground cinnamon
12 - 1/4 teaspoon salt
13 - 1/2 cup unsalted butter, cold and cubed