Drain the cherries. Line the hollows of a muffin tin with paper baking cups. Cut the cherries roughly into pieces. Chop chocolate. Mix flour, baking powder and sugar in a bowl. Whisk egg, buttermilk and oil. Add the flour mixture and mix briefly.
Fold in cherries and 75 g chopped chocolate. Spread the mixture into the bowls. Bake in the preheated oven (electric cooker: 175 °C/ convection oven: 150 °C/ gas: level 2) for 20-25 minutes (stick test!). Remove the muffins and let them cool down. Melt the remaining chocolate over a warm water bath and draw thin lines over the muffins. Leave to dry
waiting time approx. 1 1/4 hours