1. Mix crushed cookies and melted unsalted butter, put it on the bottom of the tray, press it firmly and put it in the refrigerator. 2. Mix egg yolk, sugar and vanilla extract, add fresh cream and mix. 3. Stir on low heat, heat until slightly thickened, remove from fire, add dark chocolate and mix. 4. Add sugar powder, add the already whipped cream, mix, place in the tray and harden for more than 6 hours or overnight in the refrigerator. 5. Melt dark chocolate and fresh cream in a microwave oven for 30 seconds, pour it over a solid mousse, flatten it, and harden it for 30 minutes in the freezer.