Soak the raisins in water for about 20 minutes. Cut the vanilla pod lengthwise and scrape out the pulp. Put sugar, syrup, oil, plum puree, egg white, eggs, vanilla pulp, oat flakes, oat bran, flour and baking powder into a mixing bowl.
Drain the raisins and dab dry. Mix the raisins and remaining ingredients with the dough hooks of the hand mixer. For each cookie, place 1 heaped tablespoon of dough on a baking tray lined with baking paper and press flat.
(6 cookies fit on one baking tray.) Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) on the 2nd rack from above for approx. 20 minutes. Remove the tray and let the cookies cool down on a cake rack.
Bake the rest of the dough in the same way. Apple tastes good with it.