Preheat oven to 350°F (175°C) and grease a 9-inch springform pan. Mix graham cracker crumbs, sugar, and melted butter, then press this mixture firmly into the bottom of the prepared pan and bake for 8-10 minutes.

In a large bowl, beat softened cream cheese with granulated sugar and vanilla extract until smooth. Beat in the eggs one at a time, ensuring each is incorporated before adding the next, then gently mix in the sour cream or Greek yogurt until just combined.

Wrap the bottom of the springform pan with aluminum foil, pour the filling over the baked crust, and place the pan in a larger roasting pan. Fill the roasting pan with about 1 inch of hot water to create a water bath, and bake for 60-70 minutes until the edges are set and the center is slightly jiggly.

While the cheesecake bakes, combine blueberries, sugar, and lemon juice in a saucepan, simmer for 5-7 minutes until the berries soften, then stir in the cornstarch slurry and cook until thickened. Remove from heat and let cool completely.

In a medium bowl, combine flour, sugars, and cinnamon, then cut in the cold butter with your fingers or a pastry blender until coarse crumbs form. Spread the crumble on a small baking sheet and bake alongside the cheesecake (or separately at 350°F/175°C for 10-12 minutes) until golden brown and crispy.

Once the cheesecake is cooled to room temperature, spread the cooled blueberry topping evenly over the top, then sprinkle with the cooled crumble topping. Refrigerate the cheesecake for at least 4 hours, or preferably overnight, before slicing and serving.