Preheat oven to 350F.
Start by making the apple pie filling. Melt the butter in a pot then add the diced apples. Toss to coat in the butter then add the brown sugar, cinnamon, nutmeg, lemon juice, corn starch and water. Mix well and cook over a low flame for 10 minutes, stirring often.
While the apples are cooking, prepare the crumble topping by mixing together the melted butter with the oats, flour, cinnamon and brown sugar. Use a fork to form the crumbs. Set crumbs aside.
Remove the apples from the heat and cool.
Whip the cream cheese with the sugar, vanilla, and flour in the bowl of a mixer or with a hand mixer. Add the egg and whip again.
Start layering the cheesecake. Pour the cheesecake mixture into the Kemach graham cracker crust. Top with the apple pie filling followed by the crumble. Bake at 350F for 40-45 minutes. Cool for 1 hour then store in the fridge for 4 hours or overnight.
Serve with ice cream and caramel sauce if desired.