Set the oven temperature to 320°F (160°C) and line the bottom of a 15cm (6-inch) round cake pan with parchment paper.

In a clean mixing bowl, combine 3 egg whites, a pinch of salt, and ½ teaspoon of lemon juice. Beat the mixture on medium-high until it becomes frothy (about 5 to 7 minutes).

Gradually add 75g of sugar in small increments, continuing to beat until stiff peaks form.

Add 3 egg yolks to the bowl and whisk on the lowest speed until well combined.

Sift in 70g of cake flour in two batches, folding it gently until just blended. Ensure there are no lumps, then set aside.

In a separate bowl, add 20g of cocoa powder to 30g of milk and 30g of vegetable oil. Whisk together until smooth and well combined.

Scoop out half of the dry mixture (from Step 5) and add it to the bowl with the wet ingredients (from Step 6). Whisk until well blended, then fold this mixture back into the remaining dry ingredients until just combined.

Pour the cake batter into the prepared pan and tap gently to release any large air bubbles. Bake it for 40 to 45 minutes or until a toothpick poked into the cake's center comes out crumb-free.

Once baked, remove the cake from the oven and let it rest in the pan for about 10 minutes. Then, carefully take it out of the pan and transfer it to a wire rack to cool completely.

When the sponge cake is cool, cut it horizontally into 3 layers.

In a clean bowl, add 250g of mascarpone and lightly beat with a spoon to soften. Then, add 300ml of heavy cream, 30g of cocoa powder, and 40g of powdered sugar. Mix until well dissolved.

Add a small amount of the mixture to a bowl with 120g of melted chocolate. Whisk until blended, then pour this chocolate back into the main mixture and stir until evenly combined.

Place a 16cm cake mold on a serving plate, cover the bottom with cling film, and line it with an acetate sheet.

Place the bottom cake layer into the mold and spread ⅓ of the chocolate cream filling evenly over its surface. If the mixture thickens, microwave it for 20 to 30 seconds.

Wait until the filling sets slightly, then place the second cake layer on top and spread another ⅓ of the chocolate cream filling over it.

Place the top cake layer on the filling-covered second layer, then spread the remaining filling over the top. Let it drip down the sides if desired.

Use an offset spatula to smooth the ganache over the top and sides for an even finish. Place the cake in the fridge to chill for 3 hours.

In a small saucepan, add 60g of sugar and 30g of cocoa powder. Stir for 1 to 2 minutes, then add 100ml of water and 75ml of heavy cream. Whisk until well blended.

Heat the saucepan over medium heat, bringing it to a boil.

Remove from heat, then add 3g of bloomed gelatin sheets and 70g of dark chocolate, stirring after each addition. Sift the mixture to remove any lumps or bubbles.

Let it cool to 90°F (32°C) at room temperature.

Take your homemade cake out of the fridge. Dip a palette knife in hot water and use it to smooth the top and sides of the cake.

Gently stir the chocolate glaze one last time (avoid creating bubbles), then pour it over the cake.

Let the cake set for 30 minutes at room temperature, then decorate the top as desired. Enjoy your beautiful frosted cake!