Step 1

Preheat the oven to 180℃ (350℉, Gas 4).

Step 2

Place the butter, sugar and chocolate in a large pan over a very low heat and leave to melt. Stir until combined. Remove from the heat and allow to cool a little.

Step 3

Separate the eggs and beat in the yolks along with the marsala.

Step 4

Sieve in the cocoa powder and stir. Then add the polenta and ground almonds and stir until just combined.

Step 5

Whisk the egg whites in a clean bowl until stiff. This is easiest done with electric beaters, but you can do it by hand if you're feeling strong. Fold carefully into the chocolate mixture.

Step 6

Bake in a 20cm (8") prepared round cake tin for 30 minutes or until firm to the touch.

Step 7

Leave to cool for a few minutes, then turn out onto a wire rack to cool completely.

Step 8

Sprinkle with a little sieved icing sugar and serve with raspberries.