Preheat the oven to 170°C (340°F) and prepare a 38 x 26 cm (15 x 10 in) baking pan with parchment paper.

Melt 120g dark chocolate chips and 30g unsalted butter in a heatproof bowl over a double boiler. Stir in 30ml milk once melted.

Separate 4 eggs into two bowls: whites in one, yolks in the other.

Whisk egg whites with a pinch of salt until foamy, then gradually add 50g sugar in 3 batches, beating to stiff peaks.

Whisk egg yolks with 1 tsp vanilla extract until pale and fluffy.

Fold egg yolks into melted chocolate, then gently fold in 1/3 of the egg whites, followed by the remaining egg whites.

Pour batter into the pan and smooth it out. Bake for 20-25 minutes at 170°C (340°F) until the cake is set and springs back when touched.

Cool the cake completely on a wire rack after running a knife around the edges.

Melt 90g heavy cream with 150g dark chocolate over a double boiler, then set aside to cool.

Whip 300g heavy cream with 30g sugar until soft peaks form, then fold 1/3 into the cooled chocolate mixture. Gently fold in the remaining whipped cream.

Trim the edges of the cake and cut into 3 even pieces.

Make cocoa syrup by dissolving 75ml hot water, 7g cocoa powder, and 25g sugar, then let it cool.

Assemble the cake by brushing each layer with cocoa syrup and topping with chocolate cream, stacking the layers on top of each other. Refrigerate for 3 hours to set.

Bloom 9g gelatine in 45 ml cold water for 10 minutes. In a saucepan, combine 115g sugar, 50g cocoa powder, and 85 ml water, then add 85g heavy cream and bring to a boil.

Add bloomed gelatine to the hot mixture, stir until dissolved, then strain to remove lumps and let it cool for 1.5-2 hours until it reaches 30°C (86°F).

Pour the cooled glaze over the chilled cake, letting it drip down the sides. Let the glaze rest in the fridge for 30 minutes.

Slice and serve, dipping your knife in hot water for smooth cuts. Optionally decorate with edible gold leaves.