20cm8in spring-form tin, greased and lined with baking parchment
Instructions
Set the oven to 180°C/Gas Mark 4.
Put the chocolate into a heatproof bowl and microwave on High for 2 mins. Stir to check the chocolate has melted. Microwave for 30 seconds longer if needed. (Alternatively, put chocolate in a bowl over a pan of simmering water, until it melts.)
Cream the butter and sugars together, until light and fluffy. Gradually whisk in the eggs, add the chocolate, then mix in the yogurt and vanilla essence.
Fold in the flour, baking powder and bicarbonate of soda until combined. Spoon the mixture into the tin. Bake for 45 mins, then turn off the heat and leave the cake in the oven for 45 mins, to cool slowly.
Arrange raspberries on top of cake and dust with icing sugar. Cut into slices to serve.
Notes
The cake may sink if you take it out of the oven too soon – don't worry, it still tastes scrummy. Try filling it with fruit and serving as a pud