Preheat the oven to 175°C. Separate the egg yolks from the whites, keeping the yolks ready in a small bowl. Whisk the egg whites in a stand mixer until stiff, then transfer them to the large bowl you'll use to make the batter.

Put the egg yolks in the mixer bowl – no need to wash it after the egg whites. Add the sugar to the yolks and whisk. Gradually add 18 tablespoons of hot water, whisking until the sugar dissolves and you get a wonderful sweet yolk cream.

You'll have the whisked egg whites in the large bowl. Alternately fold in the flour-cocoa mixture and the yolk cream. Fold gently so you don't knock too much air out of the whites.

Split the sponge batter evenly between the three prepared tins – the pots you've greased and dusted beforehand. All three will fit side by side on one oven rack. Bake for about 45 minutes.

Don't open the oven for the first half hour, or the sponge might sink. After that, you can check if it's done – the centre should feel firm to the touch. Confirm by inserting a skewer into the middle: if it comes out clean, it's ready.

Take all three tins out onto a wire rack and let them cool completely. Once fully cooled, turn the sponges out.

In a small pot, bring 300 ml of whipping cream to the boil. Remove from the heat and add 90 g of Willie's Cacao Venezuelan Black Carenero chocolate, chopped into smaller pieces beforehand. 90 g is one of the two bars you'll find in the pack.

Let the chocolate sit in the hot cream for about five minutes, then stir with a whisk. Fit the whisk attachment to your mixer and beat the butter and icing sugar together in the bowl. Add the chocolate mixture a spoonful at a time.

Once everything is combined, start adding the mascarpone – about half a tub at a time, whisking thoroughly after each addition. Work in the full 1 kg of mascarpone this way.

Give the finished whipped cream a good, thorough stir with a large wooden spoon so it's not too airy – otherwise the cake layers might slide around.

Bring another batch of cream to the boil – 100 g this time. Add 90 g of chopped Willie's Cacao Venezuelan Black Carenero chocolate.

Let it sit for five minutes, then stir with a whisk. Gradually fold in the sour cream, mixing it into the chocolate mixture. The resulting cream will be a bit darker than the mascarpone cream. Use it to join one or two layers of the cake.

Your creams are ready – chill them in the fridge for an hour. Cut the sponges: you have three baked sponges in total, and each should be sliced twice, giving you three layers per sponge. Spread raspberry jam over each layer.

The base of the cake will be the sponge baked in the 19 cm pot. Start with the darker sour cream chocolate mixture to join the first two layers together. Depending on how much cream you use, you might even be able to join the second and third layers too.

If the darker cream isn't enough, add a bit of the mascarpone cream too. Smooth the sides – you don't need a perfect finish yet, just fill in enough cream to make the sides smooth with no gaps. Chill this first assembled sponge in the fridge.

Continue with the other two sliced sponges, now using the mascarpone cream. Portion it out so you have enough left to cover the whole cake once it's assembled. Fill each sponge layer with cream and smooth the edges so the sides are even.

Chill in the fridge, ideally for three to four hours – overnight is fine too.

Now stack all the sponge sections together, with the 19 cm one at the bottom, of course. Join the layers with wooden cake dowels, trimmed so they're fully hidden inside the cake. Cover the sides and top of the cake with the remaining cream.

I finished mine by drawing lines all the way around the sides with a fork. I set the cake on a turntable and ran the fork around it until the lines formed. Chill the cake in the fridge for an hour before moving on to the final touches.

Bring 100 g of cream to the boil. Break in the Willie's Cacao Rio Caribe Gold chocolate and let it sit for five minutes, then stir with a whisk to make a chocolate ganache. Let it cool, then spread the cooled ganache over the sides of the cake to fill in the ridges left by the cream.

Smooth the ganache neatly, then arrange the raspberry pralines on top of the cake. And that's it – you're done! Hooray!