Step 1

Preheat oven to 180°C. Line a 20cm square cake tin with non-stick baking paper.

Step 2

Melt butter and chocolate together in a medium saucepan over low heat. Stir in brown sugar and vanilla.

Step 3

Add flour and eggs and beat with a wooden spoon until well combined. Stir in choc bits and nuts.

Step 4

Pour into prepared tin and smooth surface. Bake for 30-40 minutes until set. Remove from oven. Cool in tin for 5 minutes then transfer to a wire rack. Cut into squares to serve.