Preheat your oven to 180°C (356°F).

Beat the softened butter with ½ cup of sugar until creamy. Add the egg, flour, and baking powder, mixing until a soft dough forms.

Roll out the dough between two sheets of parchment paper and press it into the prepared springform pan, covering the base and sides evenly.

Whip the cream to stiff peaks and set aside. In a larger bowl, combine quark (or cream cheese and Greek yogurt), 1 cup of sugar, eggs, corn starch, lemon zest, and vanilla extract until smooth. Gently fold in the whipped cream.

Pour the filling into the crust. Bake for 30 minutes, then make a circular incision around the edges. Bake for another 30 minutes until the filling is set but slightly jiggly.

Turn off the oven and crack the door open, allowing the cheesecake to cool inside for 1 hour.

Remove the cheesecake from the pan and chill in the fridge for at least 4 hours or overnight before serving.