Preheat the oven to 180°C (350°F) on conventional heat.

Grease a cake pan and line the bottom and sides with parchment paper.

Sift the flour and cocoa powder with the baking powder and mix with a whisk.

Place the eggs, vanilla sugar, and regular sugar in a large mixing bowl because the mixture will triple in volume.

Place a little boiling water in another slightly smaller bowl for a bain-marie. The bottom of the bowl containing the eggs and sugar should touch the water, but the water should not rise up the sides of the mixing bowl.

Place the mixing bowl with the eggs and sugar over the bowl with hot water.

Beat for 15 minutes, or more depending on the power of your mixer. The mixture should triple in volume, become pale, and very creamy. The whisk should leave trails.

Remove from the double boiler. The sabayon should be cold; otherwise, continue to whisk it, outside of the double boiler, to cool it down.

Fold in the mixture of flour, cocoa, and baking powder in 4 or 5 additions. Gently work from bottom to top without whisking to avoid deflating the mixture.

Fill the mold and immediately place it in the oven for 55 minutes, a little more or a little less depending on the oven.

Check for doneness at three quarters of the baking time.

At the end of the baking time, check with a skewer inserted into the center of the sponge. The skewer should come out dry, without any trace of batter. Leave the cooked sponge in the turned-off oven, with the door slightly ajar, for 5 minutes.

Remove the sponge from the mold onto a wire rack and let it cool before cutting it into 3 discs.

Melt the chocolate in a double boiler or microwave, stirring it several times to mix well.

Spread it thinly on the work surface.

Once the chocolate starts to set and is no longer sticky, create curls using a dough scraper (see at 2:47 minutes in the video).

You can make shavings with a chocolate bar and a vegetable peeler. Just soften the chocolate bar slightly.

You won't need to prepare a syrup if you're using cherries in syrup, as their syrup will be used to soak the sponge cake.

Put the water, sugar, and vanilla sugar in a saucepan with 5 cherries and bring to a boil.

Remove from heat as soon as the sugar has completely dissolved.

Let it cool before using.

Flavor with kirsch if desired (about 2 tablespoons, to taste).

Use a cream with 35% fat content if possible. The richer the cream, the firmer and better the whipped cream will be.

Chill the cream and the bowl in the refrigerator or for about fifteen minutes in the freezer. They need to be very cold.

The powdered sugar should be very fine or sifted.

Place the cream in the bowl of a stand mixer and start whisking at medium speed to avoid splattering.

As soon as the cream begins to thicken, add half of the powdered sugar.

Increase the speed to the maximum setting on the mixer until the cream starts to achieve a good consistency.

Stop the mixer before the whipped cream is fully firm to taste and check the sweetness. Add the remaining sugar according to your taste.

Whisk at maximum speed until you achieve a firm whipped cream.

Place the whipped cream in a piping bag, preferably without a tip.

Place a gold cake board on a serving plate and cover the edges with pieces of freezer bag, just on the edges.

Place a sponge cake layer on top and brush it with syrup using a pastry brush.

Pipe a layer of whipped cream on top and spread it evenly.

Place the cherries over the entire surface.

Press the cherries slightly into the whipped cream.

Soak the second sponge cake layer on the side that will be against the cream, then place it on the cherries. Then, soak the top.

Spread a second layer of whipped cream on top and add cherries.

Soak the last layer of sponge cake on the side that will be against the cream, then place it on top of the cherries. Soak the top as well.

Smooth out any cream that has spilled over the sides.

Put the remaining whipped cream into a piping bag fitted with a Wilton 1M or 2D tip and pipe rosettes around the edge. The decoration is up to your preference.

Cover with chocolate shavings and place cherries on top of the rosettes.

Once the Black Forest cake is finished, refrigerate it for at least 4 hours; it will only get better. I often assemble it a day before serving or in the morning for the evening.