Steps 1 and 2
Preheat the oven to 200°C (approximately 400°F). Line a muffin tin with paper cases or grease the wells with butter.
Mix the flour, baking powder, salt and half of the sugar.
Whisk the eggs, remaining sugar, vanilla sugar and lemon zest. Stir in the milk and yogurt.
Stir the flour mixture into the egg mixture until smooth. Do not overstir.
Pour the batter into the muffin tin. Bake for about 25 minutes, until golden brown and a toothpick inserted into the center comes out clean. Let cool and serve.