Apple Filling: Preheat oven to 375°F. Heat ghee in large skillet set over medium heat; cook apples, brown sugar, granulated sugar, lemon juice, vanilla, cinnamon and nutmeg for 10 to 12 minutes or until apples are tender. Sprinkle with cornstarch; cook for 1 to 2 minutes or until filling is thickened. Let cool slightly.
Topping: Stir together flour, brown sugar and cinnamon. Toss with ghee until well combined.
Crust: Spoon filling into crust; smooth top. Sprinkle evenly with topping. Bake for 20 to 30 minutes or until topping is golden brown and filling is hot and bubbling. Let cool.