1. Start with the streusels by combining flour, sugar, cocoa powder, and salt in a bowl. Add the butter in small pieces and rub everything between your fingers to create different-sized streusels. Place them in the fridge until needed.

2. Roughly chop the chocolate for the cheesecake filling and melt it slowly either in the microwave or in a bowl over a pot with simmering water. Set aside and let cool down slightly.

3. Preheat the oven to 180°C (350°F). Line a 24cm springform pan* with parchment paper and lightly grease. Set aside.

4. Separate the eggs and add the egg whites and yolks to separate bowls. Beat the egg whites until stiff peaks form, gradually adding about a 1/4 cup (50g) of the sugar. Set aside. Mix the egg yolks with the remaining sugar (1/2 cup/100g) and the vanilla extract until the mixture looks light and fluffy. Add the low-fat quark and cream cheese and mix until well combined. Add the melted (and slightly cooled) chocolate and stir it in. Next, add the beaten egg whites and fold them in carefully. Pour the mixture into the prepared springform tin and smooth out the top. Sprinkle the streusels on top and bake the cake in the preheated oven for about 50-60 minutes – the cheesecake mixture should still wobble slightly when you tap on the baking tin. Remove the cake from the oven and let it to cool down completely inside the baking tin. When cooled, place it in the fridge for another 2-3 hours.

5. While the cheesecake is cooling, prepare the cornflake crunch – melt the chocolate and then mix it with the cornflakes until the cereal is coated evenly with chocolate. Spread the cornflakes on a piece of baking parchment and leave to dry. Break the dried cornflakes into pieces and sprinkle them on top of the cooled cheesecake. The cheesecake tastes great with a little vanilla custard or some whipped cream.