Put butter in pieces and sugar in a bowl. Beat until creamy with the whisks of the hand mixer. Mix in vanillin sugar and egg. Sift the flour and mix with baking powder and a pinch of salt. Add to the butter-sugar mixture and continue beating at medium speed until everything is well mixed. Fold in oat flakes and raisins
Line 2 baking trays with baking paper. Use a tablespoon to cut off approx. 30 portions, shape them into balls with your hands, spread them on the baking trays, flatten them with a fork and bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 15-17 minutes
Take it out of the oven. Leave to cool for approx. 5 minutes on a baking tray, place on a cake rack and allow to cool