Ingredients

For the Cocoa Sponge Cake:

• 6 eggs
• ¾ cup + 2 tbsp sugar
• 1 ½ cups flour
• ¼ cup unsweetened cocoa powder

For the Mousse:

• 14 oz dark chocolate
• 1 ⅔ cups vegetable cream
• 3 tbsp icing sugar
• 1 ½ tbsp butter
• ¼ cup rum

For the Rum Syrup:

• ¾ cup + 1 tbsp water
• ½ cup sugar
• 3 tbsp rum

Method

Prepare the Cocoa Sponge Cake:

1. Beat the eggs and sugar:
   In a large bowl, beat the eggs and sugar together very well for about 15 minutes (using a whisk or stand mixer) until the mixture becomes thick and light. The mixture should be able to “write” (leave a trail) when lifted.
2. Add the flour and cocoa:
   Sift the flour and cocoa powder together, then add them to the egg mixture a little at a time. Incorporate gently with upward movements to avoid deflating the batter.
3. Bake the cake:
   Once the mixture is smooth, pour it into a buttered and floured cake pan (24 cm in diameter). Bake at 350°F (180°C) for 40-45 minutes, or until a toothpick inserted into the center comes out clean. Let the cake cool with the oven door slightly open, then remove it from the oven and cover it with a cloth to keep it soft.

Make the Mousse:

4. Melt the chocolate:
   In a bain-marie (double boiler), melt the dark chocolate with the butter, stirring occasionally until smooth. Remove from heat and let it cool slightly.
5. Whip the cream:
   In a separate bowl, whip the vegetable cream with the icing sugar until stiff peaks form.
6. Combine the chocolate and cream:
   Gradually add the melted chocolate to the whipped cream, then add the rum. Mix gently using folding movements (top to bottom) until smooth. Place the mousse in the fridge for about 20 minutes to set.

Make the Rum Syrup:

7. Prepare the syrup:
   In a small saucepan, bring the water and sugar to a boil, then remove from heat. Add the rum to the syrup. For a non-alcoholic version, add the rum at the beginning and boil for 2 minutes to cook off the alcohol.

Assemble the Cake:

8. Layer the cake:
   Cut the cocoa sponge cake into 3 even layers. Generously soak each layer with the prepared rum syrup.
9. Add mousse layers:
   Spread a layer of rum mousse on top of each soaked cake layer, repeating the process until you reach the top layer.
10. Final decoration:
    Cover the top of the cake with the remaining mousse. Decorate as desired — you can use chocolate shavings, cocoa powder, or whipped cream for extra flair.