Line the troughs of a muffin tin (12 troughs) with baking cups. Clean and wash the rhubarb, halve it lengthwise and cut it into small pieces. Mix flour, baking powder, cinnamon and sugar in a bowl. Whisk egg, milk, yoghurt and oil. Add the flour mixture, mix briefly. Fold in rhubarb
Spread the mixture into the moulds. 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. Whipped cream tastes good with them