Preheat oven to 400 degrees F (205 degrees C).
Into a mixing bowl, add Macintosh Apples (5), Ground Cinnamon (1 tablespoon), Brown Sugar (4 tablespoon), and Vanilla Extract (2 teaspoon). Toss everything together.
Into another mixing bowl, add All-Purpose Flour (3/4 cup), Brown Sugar (1 cup), and Salted Butter (1/2 cup). Using a pastry blender or a fork, crumble the mixture together until it forms pea-sized crumbs.
Add Quaker Oats® Old Fashioned (3/4 cup). Mix well to combine.
Transfer the apples to an 8 by 8-inch greased baking dish. Sprinkle the crumble topping evenly over top. Top with Ground Cinnamon (1/2 teaspoon).
Bake for 45 minutes-1 hour.
Serve with ice cream if desired.