Quarkbällchen (German quark doughnut balls)

Step 1: Whisk 9 oz quark (or thick, strained curd cheese), 2 eggs, 1 ¾ oz sugar, 1 tsp vanilla extract, ½ tsp lemon zest and 1 pinch salt until smooth.

Step 2: Sift in 9 oz plain flour and 2 tsp baking powder and stir with a spoon into a soft, slightly sticky dough. Stop as soon as it comes together; overmixing makes them tough.

Step 3: Deep-frying safety: use a heavy, deep pan no more than a third full of oil, keep children well away from the stove, and never leave hot oil unattended. Heat 4 ¼ cups vegetable oil in a deep, heavy pan to 350°F, when a cube of bread turns golden in about 60 seconds.

Step 4: With two oiled teaspoons, drop walnut-sized balls of dough into the oil, 6–8 at a time. The common mistake is making them too big: large balls stay doughy in the middle.

Step 5: Fry for 4–5 minutes, turning, until deep golden all over; they often turn themselves. Break the first one open to check it is cooked through and fluffy with no wet dough.

Step 6: Drain on kitchen paper for a minute, then roll in 3 tbsp sugar mixed with ½ tsp ground cinnamon, if using. Cool for a few minutes before serving. Best eaten the same day.