• Preheat the oven to 350°F. Coat a 9″ springform pan in nonstick spray and line the sides with strips of parchment paper. Place a round of parchment paper on the bottom of the pan. Make sure the sides of the pan are greased very well to prevent any sticking.

Crumble topping

• In a bowl, mix together ½ cup of flour, ½ cup of rolled oats, ½ cup of brown sugar, 1 teaspoon of ground cinnamon, and ½ teaspoon of kosher salt to make the crisp topping. Pour in 5 tablespoons of melted butter and mix together until clumps begin to form and there are no more dry spots. The crisp topping should look like wet sand. Set aside in the fridge to chill while you work on the rest of the cheesecake.

Graham cracker crust

• In a bowl, combine 2 cups Graham cracker crumbs, 1 teaspoon of ground cinnamon, ¼ cup brown sugar, ¼ teaspoon kosher salt, and 8 tablespoons of melted and slightly cooled unsalted butter. Combine until evenly moistened and a wet sand-like texture is created. This recipe makes a thick crust that reaches up the sides of the cheesecake. If you prefer less crust, cut the recipe in half.
• Pour the crust into the greased and lined pan and spread into a loose even layer with your fingers. Then use the bottom of a flat measuring cup to press it into the bottom and up the sides. Bake for 8-10 minutes, until the crust is a nice golden brown. Place on a cooling rack and allow the crust to cool while you make the apple topping and cheesecake batter.

Apple topping

• Toss the apple chunks with 1 teaspoon of cinnamon, 3 tablespoons of light brown sugar, and 1 tablespoon of flour in a bowl. Place in the fridge to chill while you work on the cheesecake filling.

Cheesecake filling

• Drop the oven temperature to 325°F. Place a large roasting pan on the bottom rack of the oven, and make sure the second rack is positioned in the middle above it. Start a pot of boiling water (about 6 cups) on the stove. This will be for the water bath that goes into the roasting pan underneath the cheesecake.
• Add 4 blocks of softened room temperature cream cheese, 1 cup + 2 tablespoons of brown sugar, and 2 tablespoons of all-purpose flour to a large mixing bowl with an electric mixer or the bowl of a stand mixer with the paddle attachment. Mix on LOW speed until it comes together and forms a smooth texture. Scrape down the bowl and mix on low for another 20 seconds.
• Next, mix in the eggs one at a time on LOW speed. Only add the next when the one prior is just incorporated. After the 2nd egg is mixed in, stop and scrape down the bowl. Mix for 20 seconds then continue with the rest of the eggs.
• Mix in the 1.5 tablespoons of vanilla, 2 teaspoons of cinnamon, ½ teaspoon of kosher salt, and 1 tablespoon of lemon juice with the final egg yolk until the mix is velvety smooth, then stop mixing! Mixing too much can incorporate too much air into the batter, which can cause it to crack later on.
• Add in the sour cream and fold into the batter using a rubber spatula until it's completely incorporated. Pour the batter into the cooled graham cracker crust, and spread it even using an offset spatula. Give the pan a couple of gentle taps against your counter to release any air bubbles.

Assemble and bake

• Top the cheesecake layer with the apple pieces, followed by the crisp topping. Try to make sure that each layer is an even layer as much as possible. Press lightly to adhere the crisp topping.
• Open the oven door and slide out the bottom rack with the roast pan on it. Carefully pour the boiling water into the pan in the preheated oven and push the rack back in. Place the cheesecake just above the roast pan on the middle rack. Quickly close the door (to stop the steam from escaping). We recommend using a baking sheet to get the springform pan in and out of the oven easily.
• Bake for 1 hour and 20-30 minutes. When the cheesecake is done, the edges should be puffed up slightly and completely set. The center will be slightly sunken down. Give the springform pan a gentle nudge. It should jiggle just slightly in the center, sort of like jello. It's almost like a "vibration" type of movement. If it wiggles any more than that, it should continue baking for another 10 minutes or so.

Cool and serve

• Turn the oven off and prop open the oven door with a wooden spoon, and with the cheesecake still inside. Leave it there for 1 hour.
• Then, take the cheesecake out of the oven and let it sit at room temperature on a cooling rack. At this point we like to run an offset spatula along the edge of the cheesecake carefully to help release any stuck bits from the edge of the pan. Let the cheesecake cool for at least another 30 minutes, preferably another hour.
• After 1 hour, place the cheesecake uncovered in the fridge for at least 4 hours but preferably overnight.
• Serve with ice cream, whipped cream, or salted caramel sauce and enjoy!
• Cheesecakes should be refrigerated and can be kept for up to 5 days in an airtight container. To freeze, make sure it's properly wrapped in plastic wrap or foil and placed in a freezer-safe bag or container. It can last up to 3 months frozen.