In a large bowl, combine flour, oats, cinnamon and brown sugar. Cut in butter until mixture has a crumbly texture. Set aside.
Grease the sides and bottom of a 13x9 baking dish.
In a small bowl, combine remaining sugar, cinnamon and cornstarch.
Place chopped and peeled apples into a large bowl. Drizzle lemon juice over apples and stir to combine. Sprinkle sugar, cinnamon and cornstarch mixture over apples and stir to combine well.
Pour apple mixture into prepared pan. Top with crumb mixture.
Bake for 45-50 minutes. Remove from oven and allow to cool slightly.
Place each serving in a bowl and top with a scoop of vanilla ice cream and caramel sauce. Store any leftovers in the refrigerator, and reheat individual servings if desired.
Video
Notes
Store left over apple crisp in the refrigerator, covered.