Step 1: Prepare the Crust
Preheat your oven to 160°C (325°F). Line the bottom of a 9-inch springform pan with parchment paper.

In a food processor, combine the graham crackers and sugar. Pulse until fine and sandy. Add the melted butter and blend until evenly mixed.

Press the mixture into the base and sides of the pan using the bottom of a glass. Bake for 10 minutes, then let cool while you prepare the rest.

Step 2: Prepare the Blueberries and Crumble
In a small bowl, mix blueberries with sugar, flour, and lemon juice. Stir gently until everything is coated and set aside.

In a separate bowl, combine the flour and brown sugar for the crumble. Pour in melted butter and mix with a fork until clumps form. Set aside.

Step 3: Make the Cheesecake Filling
In a stand mixer or with a hand mixer, beat the cream cheese on low speed for 1 minute. Add the sugar and mix for another minute until smooth.

In another bowl, stir together the sour cream, cornstarch, and vanilla until smooth. Add to the cream cheese mixture and blend until fully combined.

Add the eggs two at a time, mixing on low speed after each addition. Scrape down the sides and mix once more to ensure a smooth batter.

Step 4: Assemble the Cheesecake
Pour the cheesecake batter into the cooled crust. Spread evenly with a spatula.

Top gently with the blueberry mixture, spreading evenly. Sprinkle the crumble mixture on top of the berries.

Step 5: Bake in a Water Bath
Place the springform in a larger cake pan. Set this pan into a roasting dish. Fill the roasting pan with hot water until it reaches halfway up the sides of the cake pan.

Alternatively, wrap the springform in several layers of foil to prevent water from leaking in.

Bake for 1 hour and 20 to 30 minutes. When done, the center should have a slight wobble.

Step 6: Cool the Cheesecake
Turn off the oven and crack the door open. Let the cheesecake cool inside the oven for 1 hour to prevent cracks.

Remove the cake from the water bath and place on a cooling rack. Let it come to room temperature (about another hour).

Transfer to the fridge and chill for at least 6 hours, preferably overnight.

Step 7: Serve
Once chilled, release the cheesecake from the springform pan. Slice with a hot, clean knife for perfect edges.

Serve as is or with a dollop of whipped cream or extra fresh blueberries.