Combine all the dough ingredients in a large bowl and knead into a ball for about 10 minutes (you can add a bit more soured cream if the mixture feels dry). Cover and chill in the fridge for about 30 minutes.Preheat the oven to 180°C. Grease a 20 cm square baking tin. To make the filling, blend the egg yolks with the sugar to a light, smooth paste. Slowly start adding the white cheese and butter, one tablespoon of one, then the other, beating all the time.Add the orange and lemon zest and finally, the vanilla extract.Take the dough out of the fridge and cut off about a third. Roll the large piece out on a floured surface, then cut into a square roughly the size of your baking tray. Place in your greased baking tin, pierce a few times with a fork and bake for 10 minutes.Meanwhile, roll out the smaller piece as thinly as you can and cut it into strips of about 1 cm in width.Remove your base from the oven and lower the temperature to 160°C. Allow to cool for at least 20 minutes.In a large bowl, beat the egg whites to stiff peaks. Gently fold into the filling mixture and stir to combine.Pour the cheesecake filling onto the base and lay the dough strips diagonally over the top, making stripes or checks as you prefer.Bake for 50 minutes or until set and golden, then turn the oven off and allow the cheesecake to stand in the cooling oven for a further 20 minutes while you prepare the glaze.Combine the icing sugar with the lemon and orange juice until you achieve a runny consistency.Brush the glaze over the cheesecake whilst still warm.Allow to cool completely before serving.Notes• If you can’t get hold of soured cream, you can use another thick cream as a replacement.• If you happen to have some extra egg whites, then it won’t hurt to add them in for a more fluffy consistency.Photography by Yasin Salazar. Styling by Zuza Zak. Food preparation by Zuza Zak.