Preheat oven to 400° F.
For the crisp topping: In a medium bowl whisk together flour, oats, brown sugar and cinnamon. Cut in the butter with a pastry knife, or two forks until mixture is crumbly. Set aside.
Take 2 of the apples and small dice them. In a small pan, lightly brown the butter and add the chopped apples, brown sugar, cinnamon and vanilla. Stir over medium heat for 8-10 minutes or until apples are tender. Remove from heat.
Slice the tops off of the remaining 6 apples and use a melon baller to scoop out the core and seeds. Don't scoop all of the middle out, just enough to make a large hole for the filling.
Fill the scooped-out apples with the warm apple filling from pan. Top with a generous amount of crumble topping.
Place stuffed apples in a baking dish and bake for 10-15 minutes, covered and then another 10-15 minutes until crumble topping is crispy. Serve warm with vanilla ice cream and caramel sauce. Enjoy!