- STEP 1
Preheat the oven to 180C/350F/Gas 4. Lightly grease (or line with baking parchment), a shallow 19cm/7 1/2in square cake tin. Melt the plain chocolate in a heatproof bowl over hot water.
- STEP 2
Beat the oil, sugar, eggs and vanilla essence together in a large bowl.
- STEP 3
Stir in the melted chocolate, then beat well, until evenly mixed.
- STEP 4
Sift the flour and cocoa powder into the bowl and fold in thoroughly.
- STEP 5
Stir in the chopped nuts. Tip into the prepared tin and spread evenly to the edges.
- STEP 6
Bake for 30-35 minutes, until the top is firm and crusty. Cool in the tin before cutting into squares.