Gluten-free mocha cake

Preheat oven to 180 C / Gas 4. Line the bottom of a 23cm round cake tin with parchment paper.

Bring butter, espresso and sugar to the boil in a medium saucepan, stirring to dissolve sugar.

Place chocolate in a large bowl and add boiling hot espresso mixture. Whisk until smooth. Cool slightly. Whisk in eggs. Pour batter into prepared tin.

Place cake tin in a roasting tin. Pour enough hot water into the roasting to come half way up the sides of the cake tin. Bake until centre of cake is set and a cocktail stick inserted comes out clean with a few moist crumbs attached, about 1 hour. Remove from water. Chill overnight.

Puree raspberries in processor. Chill. Serve with chilled cake.