Chocolate caramel banana mousse cake

This was one of my sons birthday cakes. He loves bananas, and he especially loves them in desserts. One of his favorite is Banoffee pie. And although I am not a big fan of bananas, I cant argue on this one. I eat it too, and I love it. Its so hard to resist the gooey caramel, bananas, whipped cream, and chocolate shavings.
So, I decided to make him a cake that will have similar ingredients, but that will be more elegant and sophisticated. And I was so happy with the result. Its two layers of chocolate sponge cake with pecans, that I soaked with rum syrup, chocolate mousse, dulce de leche mousse, and banana slices.

For sponge cake:
6 egg yolks
125 gr sugar
3 egg whites
50 gr flour
25 gr cocoa powder
50 gr pecans + 50 gr sugar (grinned together in food processor until fine powder)
50 gr hot melted butter

Preheat oven to 350F/180C. Combine the egg yolks with half of the sugar and beat until light and fluffy.
Using clean bowl whip the egg whites with other half of sugar until stiff peeks. Sift the flour and cocoa powder together over egg yolk mixture. Scoop about one third of the meringue on top and quickly and thoroughly mix it with a rubber spatula. Add remaining meringue and gently fold it into the batter. When almost completely incorporated, add pecan and sugar powder, and fold until completely mixed. Slowly pour the melted butter over the batter and fold it in. Bake in two 9 inch / 23 cm pans lined with parchment paper for 20-25 min until spongy.

Brushing syrup:
6 tablespoons water
1 tablespoon sugar
3 tablespoons rum

6 bananas

Chocolate mousse:
350 gr heavy cream
1 tablespoon sugar
100 gr chocolate
3 egg yolks
1 teaspoon gelatin
2 tablespoons cold water
First bloom gelatin in cold water. When its ready melt it in a microwave or in the hot water bath.
To make the mousse, bring 100 ml of  cream to a boil. Add chocolate and stir as it melts. Add melted gelatin.
Whisk the egg yolks with sugar until frothy and fold into the chocolate mixture. Cool to 95F/35C.
Whip the remaining cream until stiff and fold in the chocolate mixture.

Dulce de leche mousse:
350 ml heavy cream
1 egg
150 gr dulce de leche
1 teaspoon gelatin
2 tablespoons water
vanilla
Bloom gelatin in water, and dissolve in microwave or in hot water bath.
Heat  150 ml of cream with the lightly beaten egg for 10 min to 158F/70C. Mix constantly. Add dissolved gelatin, dulche de leche and mix until incorporated. Whip the remaining cream until stiff, and fold in the chocolate mixture.

To assemble the cake, brush chocolate sponge layer with brushing syrup. Put it in the spring form cake pan. Layer it with sliced bananas ( I needed 3 smaller bananas per layer, and mixed them with few drops of lemon juice to prevent them from discoloring ). Pour the chocolate mousse over bananas, and put it in the freezer until you make dulce de leche mousse.
Soak second sponge layer with brushing syrup. Put it on the top of the chocolate mousse. Layer it with sliced bananas, and pour dulce de leche mousse on top. Put it in the fridge overnight to set.
I decorated it with chocolate colar and with whipped chocolate cream.