Beat the eggs with the sugar and vanilla sugar until foamy. Now add the oil and whisk briefly. Mix the baking powder and lemon zest with the flour and slowly add to the eggs. While doing this, mix well, preferably with a food processor, not on high speed. It should be a viscous dough.
Fill the magdalene cups (muffin cups will also work) 3/4 full with the batter. Let rest in the refrigerator for about 30 minutes.
Sprinkle each cup with a little sugar just before baking.
Bake in the oven at 180ºC to 200ºC for about 15 minutes.
Instead of lemon zest, use orange zest.
Replace about 80 g of oil with 100 ml of cream. In addition, add the chocolate chips to the mixture.