Preheat the oven to 350 °F (175 °C) and get out an 8"x8" or 9"x9" baking dish.

In a medium mixing bowl with an electric hand mixer or a stand mixer fitted with the paddle attachment, prepare the cheesecake layer by beating together the cream cheese, sugar, vanilla, and salt at medium speed until well combined, scraping down the sides of the bowl as needed. Add the egg and beat on low until well combined. Set aside.

In another medium mixing bowl, mix together all of the crisp topping ingredients. It will have the texture of wet sand. Set aside.

Prepare the filling. In a large mixing bowl, stir together all the apple layer ingredients except for the apples. Once well combined, stir in the apples and coat them in the mixture.

Spoon the apple mixture into the prepared pan, and then dollop tablespoons of cheesecake filling evenly over the top of the fruit. The fruit will not be completely covered by cheesecake filling. Distribute walnut-sized pieces of the topping over the cheesecake layer. Place the baking dish on a baking sheet to catch any spills and bake for 30 to 40 minutes or until the topping is firm and the edges are bubbly. Cool completely, about 2 hours, and then refrigerate for 3 to 4 hours to allow the cheesecake layer to firm up. Serve. Cover and refrigerate any leftovers for up to 3 days.