Preheat the oven to 325°F (165°C) and line a standard muffin tin with 12 paper liners.

In a small bowl, combine the graham cracker crumbs and 2 tablespoons of sugar. Stir in the melted butter until well combined.

Divide the crumb mixture evenly among the muffin cups, pressing down firmly to form a crust layer.

In a medium bowl, beat the cream cheese until smooth. Add 1/2 cup granulated sugar and vanilla extract, and continue beating until well combined.

Add the eggs one at a time, beating after each addition just until combined.

Spoon the cheesecake batter over the crust layer in the muffin cups, filling them about 2/3 full.

In another bowl, toss the diced apples with 1/2 teaspoon of cinnamon and 1/4 cup of brown sugar until evenly coated.

Spoon the apple mixture evenly over the cheesecake layer in the muffin cups.

For the crisp topping: In a small bowl, mix together the flour, 1/3 cup brown sugar, and 1/2 teaspoon cinnamon. Cut in the cold butter using a pastry cutter or fork until the mixture resembles coarse crumbs.

Sprinkle the crumb mixture over the apple layer in each muffin cup, distributing evenly.

Bake in the preheated oven for about 20-25 minutes or until the cheesecakes are set and the topping is golden brown.

Let them cool in the pan for 10 minutes, then move to a wire rack to cool completely.

Refrigerate the mini cheesecakes for at least 2 hours before serving for the best texture.