1. Line a 12 hole muffin tin with 10 muffin cases. Mix the flour, baking powder, bicarbonate of soda and sugar together in a bowl.
2. Fork the melted butter, eggs, yogurt and vanilla together in a second bowl until just mixed then add to the dry ingredients and fork together until just mixed. Add the raspberries and diced chocolate, mix together briefly then spoon into muffin cases.
3. Bake in a preheated oven set to 190°C (375°F) Gas Mark 5 for 15-20 minutes until well risen and golden. Leave to cool for 10 minutes then loosen the edges of the cases with a round bladed knife, lift muffins out of the tin and cool on a wire rack.
4. Decorate the muffins with melted chocolate drizzled from a spoon or piped from a paper piping bag with the tip snipped off – no need for a piping tube. Leave to harden for 5-10 minutes before serving.
Recipe courtesy of Seasonal Berries