In a large bowl mix buttermilk, oat flakes and raisins. In a second bowl mix flour, baking powder, cinnamon and salt. Stir egg white and honey into the buttermilk-oatmeal mixture and then mix with the flour mixture. Peel the apple, grate from the core and fold in
Line the troughs of a muffin tin (12 troughs) with paper baking cups. Spread the dough into the baking cups. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 20-25 minutes. Take out, let cool in the form for about 10 minutes. Take the muffins out of the tin and let them cool down on a cake rack