First Step: Prepare the Cheesecake Crust

1. Make the Crust: In a medium bowl, combine the graham cracker crumbs, sugar, melted butter, and cinnamon. Stir until the mixture is evenly combined, and the crumbs are coated in butter.
2. Press the Crust into Muffin Tins: Spoon the graham cracker mixture into the bottom of each muffin cup (use a regular 12-cup muffin tin). Press the mixture down with the back of a spoon or your fingers to form a firm crust. Be sure to press the crumbs evenly across the bottom of each cup.
3. Bake the Crust: Preheat the oven to 325°F (163°C). Place the muffin tin in the oven and bake the crust for about 8-10 minutes, or until golden brown and fragrant. Remove from the oven and set aside to cool while you prepare the cheesecake filling.

Second Step: Prepare the Apple Crisp Topping

1. Cook the Apples: In a medium saucepan, combine the diced apples, lemon juice, cinnamon, and brown sugar. Cook over medium heat for about 5-7 minutes, stirring occasionally, until the apples begin to soften. The apples should still hold their shape but be tender. Remove from the heat and set aside.
2. Prepare the Oat Topping: In a separate bowl, combine the oats, flour, brown sugar, and salt. Add the butter and use a fork or your fingers to work it into the mixture until it forms a crumbly topping. Set this aside.

Third Step: Prepare the Cheesecake Filling

1. Beat the Cream Cheese: In a large mixing bowl, beat the softened cream cheese with an electric mixer until smooth and creamy. Scrape down the sides of the bowl to ensure the mixture is even.
2. Add the Sour Cream and Sugar: Add the sour cream and granulated sugar to the cream cheese. Continue mixing until the filling is smooth and well combined.
3. Incorporate the Eggs and Flour: Add the eggs one at a time, mixing after each addition to incorporate fully. Then, add the flour and vanilla extract and mix until fully combined. Be sure not to overmix, as this can cause the cheesecake to crack during baking.

Fourth Step: Assemble the Mini Cheesecakes

1. Fill the Muffin Tin: Spoon the cheesecake filling into each muffin cup, filling it nearly to the top. Gently smooth the top with a spatula to ensure an even surface.
2. Add the Apple Topping: Spoon the cooked apples on top of the cheesecake filling, dividing them evenly among the mini cheesecakes. The apples should nestle nicely into the creamy filling.
3. Top with Oat Mixture: Sprinkle the oat topping evenly over the apples, covering the entire surface of each mini cheesecake. This creates a delightful, crumbly texture once baked.

Fifth Step: Bake the Mini Cheesecakes

1. Bake the Cheesecakes: Place the muffin tin in the preheated oven at 325°F (163°C). Bake for 25-30 minutes, or until the cheesecakes are set and the oat topping is golden and crisp. The edges should be firm, and the center should have a slight jiggle.
2. Cool the Cheesecakes: Once baked, remove the mini cheesecakes from the oven and let them cool in the tin for 10-15 minutes. Afterward, transfer them to a wire rack to cool completely. You can also chill them in the fridge for at least 2 hours (or overnight) to allow the flavors to set.

Final Step: Serve and Enjoy

1. Garnish (Optional): Just before serving, you can garnish the mini cheesecakes with a dusting of powdered sugar or a drizzle of caramel sauce for extra sweetness.
2. Serve: Carefully remove the mini cheesecakes from the muffin tin. Place them on a serving platter and enjoy the delightful contrast of creamy cheesecake, warm spiced apples, and crunchy oat topping.