Tipomisu (Tiramisu)

Instructions

1. For the chocolate brownie, preheat the oven to 170°C (325°F) and line a 25 cm (10 inch) square baking tin with baking paper. In a heatproof bowl, melt the chocolate and butter set over a saucepan of simmering water (make sure the base of the bowl doesn’t touch the water) until completely melted and emulsified. In the meantime, place the eggs, brown sugar and vanilla seeds in the bowl of a mixer fitted with the whisk attachment and whisk on medium-high speed until pale, then reduce the speed and slowly add the warm chocolate and butter mixture. Once fully incorporated, remove the bowl from the mixer and fold in the flours and cocoa with a rubber spatula until just combined, being careful not to overmix. Pour the brownie batter into the tin and bake for 20–25 minutes, or until a knife inserted into the centre of the brownie comes out clean. Leave to cool to room temperature, then chill in the fridge for several hours or overnight.
2. For the discs, temper the chocolate by melting three-quarters of it in a heatproof bowl set over a saucepan of simmering water (make sure the base of the bowl doesn’t touch the water).
3. In the meantime, finely chop the remaining chocolate. When the melting chocolate has reached 35°C (95°F), remove the bowl from the pan and add the chopped chocolate, stirring until the temperature cools to 27°C (80°F), then gently reheat over the simmering water until the temperature reaches 31–32°C (88–90°F). Otherwise, you can just melt the chocolate.
4. Spread the chocolate onto acetate or baking paper to make a sheet approximately 1 mm (1 /16 inch) thick. Once it’s partially set, use an 8 cm (3¼ inch) ring cutter to cut out 8 discs, then allow the chocolate to fully set for 3–4 hours, or preferably overnight. Carefully remove the discs from the acetate or baking paper and place in an airtight container with baking paper between each one and store in a cool place – but not the fridge – until needed. (However, if you melted the chocolate rather than tempering it, you could refrigerate the discs to try to imitate the ‘snap’ of tempered chocolate.)
5. For the mascarpone cream, place all the ingredients except the dark rum into the bowl of a stand mixer fitted with the whisk attachment. Whisk until smooth and thick – you’re after medium peaks that will hold their shape fairly well – then add the rum and whisk lightly, just to mix through the rum. Place the mascarpone cream into a piping bag fitted with a 5 mm (¼ inch) nozzle and keep in the fridge until needed.
6. To make the caramel, heat the cream in a small saucepan to just below simmering point. In a heavy-based saucepan, melt the sugar over medium heat, without stirring, until you have a golden-brown caramel, then slowly add the cream – be careful, as it could splatter and overflow if you pour in too much cream at once. Once the cream is fully incorporated, let it boil for 1 minute, then add the espresso and salt and bring back to the boil. Take off the heat and whisk in the chocolate until smooth. Pass the caramel through a fine sieve into a jug and keep warm.
7. When ready to assemble, turn out the brownie onto a chopping board. With an 8 cm (3¼ inch) ring cutter, cut out 8 discs, then use a 6 cm (2½ inch) ring cutter to remove the centre of each brownie disc to form a ring. Place a brownie ring in the centre of a plate and fill the centre with mascarpone cream. Put a chocolate disc on top, then dust generously with cocoa powder. Pipe three dollops of the mascarpone cream on top of the chocolate disc and two larger ones on either side. Spoon about 2 tablespoons of the warm caramel in the centre of the disc and serve immediately.