Two days before serving, make the cherry insert:
In a saucepan, cook the cherries with the sugar for 10 minutes. Blend, then add the drained gelatin while the mixture is still hot.
Once the gelatin is fully dissolved, blend again and pour into an insert mold. Freeze overnight.

Next, make the sponge cake:

Preheat the oven to 410°F (210°C).

Beat 2 whole eggs, 2 yolks, and the sugar for 5 minutes.
Gently fold in the sifted flour and cocoa powder.
Beat the 2 egg whites, then gently fold them in.

Spread the batter on a silicone baking mat or jelly roll pan and bake for 7–8 minutes.

Let cool.

The next day, prepare the chocolate mousse:

Heat the milk and 1 tablespoon (20 g) of the sugar.

Whisk the egg yolk with the remaining sugar. Add the cornstarch, then gradually whisk in the hot milk. Return to the heat for about 2 minutes, stirring constantly. Once thickened, remove from heat and add the chocolate. Mix until smooth.

Cover with plastic wrap directly on the surface and let cool to room temperature.

Whip the cream to stiff peaks, then gently fold it into the cooled chocolate mixture.

Next, make the Stracciatella whipped cream: Whip the cream to stiff peaks, gradually adding the sugar, then gently fold in the chocolate shavings with a spatula.

Soaking syrup:

Bring the sugar, water, and vanilla bean to a boil, then remove from heat. If desired, add a splash of alcohol once the syrup has cooled.

Assembly:

Line a yule log mold with acetate or, if unavailable, plastic wrap.

Cut the sponge cake to fit the mold, soak it with syrup, and place it on the acetate.

Cover with 3/4 of the chocolate mousse, then place the cherry insert on top and cover with a thin strip of soaked sponge cake.

Cover with 3/4 of the whipped cream, then finish with the last piece of soaked sponge cake.

Freeze for at least 1 hour.