Begin by preparing your pan and crust. Preheat the oven to 325°F and line a greased 9-inch springform pan with parchment paper.
Crush 1¼ cups (175g) of graham crackers into fine crumbs and combine them with ⅓ cup (75g) of melted salted butter and ¼ cup (55g) of demerara sugar.
Mix until the texture resembles wet sand, then press this mixture firmly into the bottom of the prepared pan to create an even, compact crust. This foundation will provide structural support for the creamy filling above.
For the cheesecake filling, beat together ¼ cup (65g) of softened salted butter with 1 cup + 2 tbsps (225g) of granulated sugar until light and fluffy.
Add 2⅓ cups (550g) of full-fat cottage cheese or ricotta, ⅓ cup (40g) of all-purpose flour, and the finely grated zest and juice of 2 lemons, beating until the mixture is smooth and well-combined.
In a separate bowl, whip ¾ cup + 1 tbsp (200ml) of heavy cream until it reaches soft peaks. In another bowl, beat the 4 separated egg whites until stiff peaks form.
Gently fold the whipped cream into the cheese mixture, then carefully fold in the stiff egg whites in two additions, being careful not to deflate them.
Pour the filling over the prepared crust and bake for 1½ hours at 325°F until the top is set but still slightly jiggly in the center. Once baked, turn off the oven and crack the door open slightly, allowing the cheesecake to cool gradually to prevent cracking.
For the topping, combine about 3½ cups (450g) of mixed summer fruits with sugar to taste and 1 tsp of arrowroot powder, then gently warm this mixture to create a glossy compote.
Serve slices of the cooled cheesecake with the fruit topping and a dollop of ⅔ cup (150ml) of freshly whipped heavy cream.