Ingredients

·         375g good quality dark chocolate

·         375g butter, cut into pieces

·         500g caster sugar

·         6 medium eggs

·         225g plain flour

For the topping (optional)

·         140g good quality dark chocolate

·         50g butter, cut into pieces

·         icing sugar for dusting

Method

·         STEP 1

Butter and line a 30cm x 21cm tin. Preheat the oven to 180C/160C fan/gas 4. Break up the chocolate with the butter and melt in the microwave on medium for about 5 minutes, stirring halfway through.

·         STEP 2

Beat the sugar and eggs in a bowl. Stir in the melted chocolate, add the flour and beat well. Pour into the tin and bake for 40-45 minutes, or until the top looks papery and feels slightly wobbly. Leave to cool in the tin.

·         STEP 3

If you're making the topping, break up the chocolate with the butter and melt in the microwave on medium for about 1 minute. Stir until smooth then spread over the cake. Dust with icing sugar and cut into squares.