1. Preheat the oven to 180°C (350°F). Line a 24cm/9.5 inches springform tin* with baking parchment and grease lightly. Set aside. Wash the blueberries and let drain.

2. Crush the shortbread cookies until you have very fine crumbs. Melt the butter and mix it with the cookie crumbs. Transfer the cookie crumbs to the baking tin and press them down with the back of a spoon to create a compact layer. Place in the fridge until needed again.

3. Add the mascarpone, cream cheese, sugar, cornstarch, vanilla paste, eggs, and lemon zest to a large bowl and mix until well combined. Fold in half of the blueberries, transfer the mixture to the baking tin and spread evenly. Sprinkle the remaining blueberries on top and press them down slightly.

4. Bake the cake for about 50-60 minutes. The edges of the cheesecake should have set, but the center of the cake should still wobble slightly when you tap the baking tin. Turn off the oven and open the door a bit. Let the cheesecake cool inside the oven for about 30 minutes, then take it out and let it cool down completely on a wire rack. Place the cake in the fridge for several hours (or overnight) before serving.