For the Cold Brew Coffee Concentrate*:
125g coffee (4bean espresso, espresso grind)
500ml room temperature water
For the Coffee Syrup*:
300ml Cold Brew Concentrate
300g Caster Sugar
For the Cake:
125g Salted butter
125g Caster Sugar
2 Eggs, Beaten
125g Self-Raising Flour
80g Dark Chocolate
For the Ganache
125ml Double Cream
250g Dark Chocolate
50ml Coffee Syrup
80g White Chocolate
For the Cold Brew Coffee Concentrate:
Mix 250ml of water with the espresso-ground coffee and leave to stand for 10 minutes.
Mix the remaining 250ml with the coffee, cover, and leave in the fridge for 24 hours.
For the Coffee Syrup:
Combine the Coffee Concentrate with the caster sugar in a small pan. Bring to the boil, turn down the heat and simmer for 15 minutes.
For the Cake:
Preheat oven to 180 degrees.
Line a 9 inch cake tin with greaseproof paper, and lightly grease the sides.
Melt the dark chocolate in a double boiler or microwave.
Cream the butter and sugar before slowly adding the beaten egg.
Fold in the self raising flour.
Spoon half the cake mixture into the tin.
Fold the dark chocolate into the remaining cake mixture.
Spoon the chocolate cake mixture into the tin, and use the end of a teaspoon to carefully marble the two mixtures together.
Bake for 25 minutes.
Remove the cake from the oven and pierce all over with a cocktail stick.
Pour over 100ml of the coffee syrup and leave to stand in the tin for 10 minutes, before turning out on a wire rack and leaving to cool completely.
For the Ganache:
Place the dark chocolate in a large mixing bowl.
Combine the double cream and coffee syrup in a small pan and gently bring to the boil.
Pour the hot cream over the chocolate. Let it stand for a minute before whisking into a smooth sauce.
Melt the white chocolate over a double boiler before placing into a piping bag or squeezy bottle.
Place the chilled cake, on its cooling rack, over a tray.
Carefully pour over the warm chocolate ganache, and spread it to drip down the sides.
Pipe or squeeze the white chocolate over the top of the cake in concentric circles. No need to be neat here, the messier the better!
Use a cocktail stick to drag lines in the white chocolate, from the edge towards the centre, to create the cobweb design.
Leave the ganache to set completely (around 1 hour) before transferring to a serving plate.
*This recipe yields more Cold Brew Concentrate and Coffee Syrup than required. The Cold Brew Concentrate is perfect for an at-home espresso martini, just shake equal parts concentrate, vodka and Kalhua over ice. The Coffee syrup is perfect for flavouring cakes, brownies and milkshakes, as well as making a delicious sweet iced coffee.