You will need


Preheat your oven to 180 degrees Celsius (conventional) or 160 degrees Celsius (fan oven) and boil some water in your kettle.

Put the dark chocolate chips into a bowl and pour over them 60ml (1/4 cup) of boiling water.

Add one shot of fresh espresso (around 30ml). You can also use instant espresso powder (1tsp) or both for extra coffee flavour.

Give your chocolate mixture a stir every now and then so that the chocolate completely melts and incorporates into the espresso and hot water.

Separate the eggs in two large bowls. Using a hand mixer, beat the egg whites until they are very firm.

Add your softened butter, sugar, salt, cacao powder and vanilla extract to the egg yolks and cream together with your hand mixer or spatula, whichever you prefer.

Once the chocolate has fully melted, add the mixture to your egg yolks & butter.

Scoop in the whipped egg whites with a spatula, folding it in carefully to preserve as much air & fluffiness in your batter.

Pour the mixture into your cake form. You can use anything you like. I went for a 26cm diameter because I like this cake to be thin (you could use a brownie tin too), but if you want a thicker cake, use a cake form with a smaller diameter. Note that this will add ±5 mins to your baking time.

Bake for 35-40 minutes, until a skewer inserted in the cake comes out clean (or you can under bake the cake for only 30 minutes, then leave it to set in the fridge for brownie-like fudge).