Chocolate and walnut brownies

Method

1. Line a 33 x 28cm Swiss roll tin with baking paper. Preheat the oven to 180C/ fan160C/gas 4.
2. Melt the butter and chocolate in a small pan over a low heat, stirring until melted. Remove from the heat and set aside to cool.
3. In a bowl, whisk the eggs and sugar, until thick and foamy. Whisk in the chocolate, then fold in the flour and walnuts. Pour and spread in the tin and bake for 20-25 minutes. To check if the brownie is cooked, push a cocktail stick into the mixture, leave for 2 seconds, then remove – if the cocktail stick is clean and not sticky, it is cooked. Cool.
4. Dust with icing sugar and, using a sharp-bladed knife, cut into 2cm square petits fours or larger slices, and wipe the knife clean often as the mixture may stick to it.