Let’s transform these ingredients into a masterpiece. Follow these steps to create your own batch of Apple Cinnamon Cheesecake Crumb Bars:

1. Preheat your oven to 350°F (175°C) and line a 9×13-inch baking dish with parchment paper, leaving extra on the sides for easy lifting.
2. In a large mixing bowl, combine the flour, 1/2 cup granulated sugar, brown sugar, baking powder, cinnamon, and salt. Stir until well mixed.
3. Using a pastry cutter or your hands, incorporate the chilled butter into the flour mixture until it resembles coarse crumbs. Stir in the beaten egg to bring the mixture together.
4. Press half of the crumb mixture into the prepared baking dish to form the crust. Set the remaining crumb mixture aside for the topping.
5. In another bowl, toss the diced apples with lemon juice and cornstarch until evenly coated. Spread the apple mixture over the crust.
6. For the cheesecake layer, beat the cream cheese and sour cream together until smooth. Add in the vanilla extract and 1/2 cup granulated sugar, mixing until fully incorporated.
7. Pour the cheesecake mixture over the apples, spreading it evenly with a spatula.
8. Sprinkle the reserved crumb mixture over the top, ensuring the surface is fully covered.
9. Bake in the preheated oven for 45-50 minutes, or until the top is golden brown and the cheesecake layer is set.
10. Allow the bars to cool in the pan for at least 30 minutes, then refrigerate for an additional 2 hours before cutting into squares.