Crumbly and delicate at the same time muffins with raisins

Ingredients:
flour – 250 g;
sugar – 200 g;
baking powder – 2 teaspoons;
egg – 1 pc.;
milk – 180 ml;
sunflower oil – 100 ml;
raisins – 120 g;
vanilla sugar – 10 g;
salt – a pinch.