Preheat the oven to 180°C.
Line a 20cm round spring-form cake tin with parchment paper (Make sure the tin is leak proof as it is a wet batter).
Start with the icing by putting all of the icing ingredients except the chopped chocolate into a heavy-based saucepan and bring to the boil, making sure everything’s dissolved.
Then turn off the heat – but leave the pan on the hob for a minute or two – then add the finely chopped chocolate and swirl the pan so that the chocolate is covered.
Leave to stand for a minute, then whisk until you have a darkly glossy icing, and leave to cool, stirring every now again while preparing the cake
Put the flour, bicarb, salt and instant espresso and cocoa in a bowl and fork to mix.
Mix together the sugar, water, coconut oil, vinegar and vanilla until the coconut oil has melted, and stir into the dry ingredients, then pour into the prepared tin and bake for 35 - 40 minutes Though do check at the 30-minute mark to see if it is already done.
When it's ready, the cake will be coming away from the edges of the tin and a cake tester will come out clean, apart from a few crumbs. This is a fudgy cake and you don't want to overdo it.
Once the cake is cooked, transfer the tin to a wire rack and let the cake cool in its tin.
Give the icing a good stir with a spatula to check it is at the right consistency. It needs to be runny enough to cover the cake, but thick enough to stay (mostly) on the top. Pour over the unmoulded cake, and use a spatula to ease the icing to the edges.
Sprinkle with chopped pistachios if using and leave to stand for 30 minutes for the icing to set before slicing into the cake.FREEZING:
The cake can be made ahead and frozen, without icing. When cool, carefully wrap cake in a double layer of clingfilm and a layer of foil. Freeze for up to 3 months. To defrost, unwrap and place on a serving plate at room temperature for 3–4 hours.
Recipe reprinted with permission of Hein Stirred
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