550 g (1 1/4 lb) plain chocolate
1 cup (225 g) butter
2 tbsp (30 ml) freshly made strong black coffee
1 cup + 2 tbsp (225 g) caster sugar (superfine granulated)
2/3 cup (75 g) (3 oz) self raising (self rising)white flour
1.25 ml (1/4 tsp) salt
175 g (6 oz) walnut halves, chopped
1 tsp (5 ml) vanilla essence
1. Grease and line a baking tin measuring 19 x 27 cm (7 1/2 x 10 1/2 inches) across the base (or use a tin with similar dimensions).
2. Using a sharp knife, roughly chop 225 g (8 oz) of the chocolate and set aside.
3. Melt the remaining chocolate and butter in a heatproof bowl over a pan of simmering water.
4. Allow the chocolate mixture to cool slightly.
5. Mix the eggs, coffee and sugar together in a large bowl until smooth, then gradually beat in the melted chocolate mixture.
6. Fold in the flour, salt, walnuts, vanilla essence and chopped chocolate.
7. Pour into the prepared tin and bake the brownie mixture at 190°C (375f/gas 5) for 40-45 minutes or until just firm to the touch in the centre.
8. Leave to cool in the tin, then turn out.
9. Trim off the crusty edges and cut into squares. Store in an airtight container for up to 1 week.
10. If freezing, open freeze then pack in freezer containers, label and freeze.
Thaw for 4-6 hours.