1. Slice the chiffon cake, shape it out with a mousse mold, and set aside. I used leftover eight-inch chiffon cake, which was divided into three slices horizontally, which was still a bit thick.
2. Melt gelatin powder with a little cold water and set aside. The same can be done with fish film, it needs to be pre-dissolved in advance, if it is directly sprinkled into the hot solution, it is easy to agglomerate. And gelatin powder should not be overheated, which will affect the degree of coagulation.
3. Add water and fine sugar to the egg yolk and put it in a pot, heat it on a low heat and stir constantly until the sugar is completely dissolved and boiling, at which time the egg yolk is already cooked.
4. After filtering, add the gelatin solution of step 2 and stir until it is completely dissolved, then sieve, and let it cool to the extent that it is not hot to your hands.
5. Melt the dark chocolate into a liquid state over a low heat, add it to the egg yolk, and stir well.
6. Whip the whipped cream until the lines appear, and add it to the chocolate liquid in the previous step evenly. This is the chocolate mousse paste.
7. Pour the chocolate mousse paste into the mold, seventy-fourths full, shake out bubbles a few times. Because you need to cover a layer of cake slices, if you don't add cake slices, just fill it up.
8. Cover with a piece of cake, pour in the remaining mousse paste, and refrigerate for more than two hours. Both chocolate and gelatin powder have a solidifying effect. If you are in a hurry, you can also freeze it.
9. While refrigerating, use water-melted chocolate to draw facial features on greased paper
10. After solidification, take it off and set aside
11. Demoulding: Wipe it with a hot towel along the edge of the spherical mould, or blow it with warm air, and push the mousse with water to demould.
12. Just insert the decorated facial features on the mousse cake
