Black Bean Brownies

Method

1. Preheat the oven to 180°C/350°F/Gas mark 4. Butter a 24-cm/9½-in square baking tin or line with baking parchment.
2. Melt the chocolate and butter together in a large bowl placed over a pan of simmering water or in the microwave on low. Leave to cool a little, then add the cocoa and vanilla.
3. Meanwhile, blend the beans with the one of the eggs in a food processor or using a hand-held blender. The mixture should be as smooth as possible, otherwise the brownies will have a mealy texture. Gradually stir the bean mixture and the nuts into the chocolate.
4. Beat the remaining eggs with the sugar until light and creamy, and then fold into the brownie mixture.
5. Pour into the tin, sprinkle with salt and bake for about 25–30 minutes, until just set but still a little wobbly.
6. Place the tin on a wire rack and leave to cool completely before attempting to cut up into small squares. (If the brownies seem very gooey, placing them in the fridge for half an hour will make them easier to slice.) In the unlikely event of leftovers, you can keep the brownies in an airtight container for up to 5 days.