75 g (3 oz) unsalted butter, softened, plus extra for greasing
300 g (10 oz) plain dark chocolate (70% cocoa solids), chopped
grated rind of 1 orange
75 g (3 oz) soft light brown sugar
50 g (2 oz) plain flour, sifted
1 tablespoon orange liqueur
vanilla ice cream or crème fraîche, to serve
Grease 6 x 150 ml (1/4 pint) metal pudding moulds or ramekins and place on a baking sheet. Melt the chocolate in a heatproof bowl set over a saucepan of gently simmering water, then add the orange rind, reserving a few strands for decoration. Once the chocolate has melted, stir until smooth, then leave to cool slightly.
Place the butter, sugar, eggs, flour and liqueur in a food processor or blender and blend to form a smooth batter. Add the melted chocolate and whizz again until well combined.
Pour the batter into the prepared dishes and place in a preheated oven, 190ºC (375ºF), Gas Mark 5, for 9 minutes. The outside should be cooked with a molten centre. Serve immediately with scoops of vanilla ice cream or crème fraîche and decorate with the reserved orange rind.