To create these delightful Apple Crisp Mini Cheesecakes, follow these straightforward steps:

1. Preheat the Oven: Preheat your oven to 325°F (165°C).
2. Prepare the Muffin Tin: Line a standard muffin tin with cupcake liners for easy removal of the mini cheesecakes.
3. Make the Crust: In a bowl, combine graham cracker crumbs, granulated sugar, and melted butter. Stir until the mixture resembles wet sand.
4. Fill the Muffin Tin: Divide the crust mixture evenly among the muffin cups, pressing it down firmly to form a solid base.
5. Bake the Crust: Bake the crusts in the preheated oven for about 5 minutes. Remove and allow to cool slightly.
6. Prepare the Cheesecake Filling: In a large bowl, beat the softened cream cheese and granulated sugar together until smooth and creamy.
7. Add Eggs and Flavor: Add the eggs one at a time, mixing well after each addition. Stir in the vanilla extract and cinnamon until fully combined.
8. Fill the Cups: Pour the cheesecake filling over the crusts in the muffin tin, filling each cup about three-quarters full.
9. Prepare the Apple Filling: In a separate bowl, toss the diced apples with brown sugar, cinnamon, and lemon juice until well coated.
10. Add Apple Topping: Spoon the apple mixture evenly on top of the cheesecake filling in each muffin cup.
11. Make the Streusel Topping: In another bowl, mix oats, flour, brown sugar, cinnamon, and melted butter until crumbly.
12. Sprinkle Streusel: Generously sprinkle the streusel topping over the apples in each cup.
13. Bake: Bake in the oven for 20-25 minutes, or until the cheesecake is set and the tops are lightly golden.
14. Cool the Cheesecakes: Remove from the oven and let the cheesecakes cool in the tin for about 10 minutes before transferring to a wire rack.
15. Chill: After cooling, refrigerate for at least 1 hour before serving to allow the flavors to meld.

Now you have delicious Apple Crisp Mini Cheesecakes ready to enjoy!