Photo by Babiche Martens
- Preheat oven to 175C.
- Grease and line a 20 x 30 cm tin.
- Place chocolate and butter in a bowl over simmering water and melt. Remove from heat.
- Add the sugar, eggs and vanilla.
- Fold through the flour and nuts.
- Pour into tin and bake for 25-30 minutes, until firm around the edges and slightly soft in the middle.
- Cool, then slice into pieces. Dust with icing sugar.