Decadent chocolate and chestnut bars Recipe

• Preheat the oven to 150°C, fan 130°C, gas 2. For the base, place the biscuits in a large bowl and crush with your hands or a rolling pin.
• Add the butter and mix to a sandy paste.
• Press firmly and evenly into a 20cm square baking tin lined with baking parchment. Leave in the fridge to set.
• Meanwhile, put the dark chocolate and butter in a heatproof bowl over a pan of simmering water and melt, stirring occasionally with a wooden spoon.
• Remove from the pan when melted.
• Use an electric mixer to whisk 2 whole eggs plus an extra egg yolk and sugar until thick and pale (save the egg white for another recipe).
• This will take 15-20 minutes. Gently fold the chocolate mixture into the eggs, then the chopped chestnuts, figs and white chocolate.
• Spread evenly over the biscuit base and bake on the middle shelf of the oven for 25-30 minutes.
• When ready, a skewer inserted in the bar will come out with lots of gooey crumb attached, and there will be a light crust on top. Cool, then refrigerate until set.
• Remove from the tin and peel off the baking parchment.
• Cut into bars (or tiny squares to serve with good coffee) and dust lightly with cocoa powder. Let them come to room temperature before serving.

Get ahead: make the bars up to 3 days ahead; they can also be frozen.