Start by making the sponge, put the egg whites into a mixing bowl and whisk gradually adding the sugar until stiff meringue consistency, with the machine still running add the yolks and once incorporated stop the machine.
Fold in the coco powder. Spread this onto a tray lined with greaseproof paper and bake in the oven at 180oc for 14 minutes. Remove from the oven and allow to cool. Once cool line a rectangle baking frames (60cmx9cmx3cm) base with the sponge.
For the cremeux whisk the yolks and sugar together until pale. Bring the milk and cream to the boil and pour on to the yolks whisking continuously, return this mixture to a clean pan and cook out slowly to 86oc. Once cooked cool to 50oc. Melt the chocolate gently over a bain marie, once melted gradually add the custard and emulsify with a bamix. Pour this into the lined baking frame and refrigerate until set.
For the ice cream whisk the yolks and sugar together until pale. Bring the milk, banana puree and cream to the boil and pour on to the yolks whisking continuously, return this mixture to a clean pan and cook out slowly until it reaches 86oc. Once cooked let the mixture cool and blitz in the stabiliser leave refrigerated for 4 hours then blitz again and freeze in paco jet canisters. Once frozen churn in the paco jet.
For the caramelia mousse soften the gelatine and melt the chocolate, make a pate a bomb with the egg yolks and sugar and add the softened gelatine. Semi whip the cream. Fold the pate a bomb into the chocolate then add the whipped cream place this into a piping bag with a nozzle.
To plate up slice the cremeux and place onto the plate, add a small amount of crushed Maldon salt, pipe on the caramelia mousse and add a roche of banana ice cream, garnish with chocolate and caramel sauce and caramelised peanuts.