Preheat your oven to 325°F. Spray a 9-inch springform cake pan with cooking spray, and line the outside bottom with tin foil to prevent water from getting into the bottom of the pan.
In a medium bowl, combine the graham cracker crumbs and granulated sugar.
Add the melted unsalted butter to the crumb mixture and mix until well combined.
Press the mixture into the bottom of a 9-inch springform pan, with the bottom of a flat cup or your hand creating an even layer. Go halfway up the sides.
Bake the crust in the preheated oven for 14 minutes.
FOR THE STREUSEL
In a medium size bowl, prepare the streusel topping. Combine the light brown sugar, all-purpose flour, ground cinnamon, and salt. Using your fingers or a pastry cutter, cut in the cold cubed butter until the mixture resembles coarse crumbs. This takes some time, so be patient. You want a shaggy look.
When the streusel is ready, place it in the fridge while you make the cheesecake batter.
FOR THE CINNAMON SWIRL
In a microwave safe medium size bowl, melt the butter.
Once the butter is melted add the rest of the ingredients and mix with a rubber spatula. Set aside.
FOR THE CHEESECAKE FILLING
Preheat your oven to 325°F. Pour water into a sheet pan or roasting pan, filling up only a little less than halfway of the pan. Set aside.
In a large mixing bowl, using a handheld electric mixer, or in a bowl of a stand mixer fitted with the paddle attachment, beat the room temperature cream cheese on medium speed until smooth and creamy.
While the mixer is on low, gradually add the granulated sugar to the cream cheese, continuing to beat until the mixture is well combined and smooth.
With the mixer on low speed, add the room temperature egg yolk and whole eggs all at once and mix just until incorporated. With a rubber spatula, scrape the bottom and the sides of the bowl.
With a rubber spatula, gently fold in the sour cream, vanilla extract, and corn starch. Fold the entire cheesecake filling until it is smooth, with no lumps remaining. Ensure you get the bottom and the sides. Be careful not to overmix, as this can introduce excess air bubbles into the batter.
Carefully pour the HALF of the cheesecake filling into the baked graham cracker crust. Spread evenly across the pan. Sprinkle the brown sugar cinnamon on top. (If the filling is slightly hard, pop it in the microwave for 10-20 seconds to soften up) Pour the remaining half of the cheesecake batter on top of the brown sugar mixture. With the back of the spoon, evenly spread the cheesecake across the top.
Take 2-3 dollops of blueberry jam and place on top, with the back of a spoon gently spread it across the top.
Sprinkle the fresh or frozen blueberries across the top and then add then generously sprinkle the streusel on top of the blueberries.
Place the cheesecake in the prepped water bath and bake for 70-80 minutes until the middle is barely set and slightly jiggled. If the cake is still jiggling, bake for 5 more minutes.
Let the cheesecake cool to room temperature and then place in the fridge for at least 4 hours to set up!