for 4 tartelettes
for the cocoa pastry (adapted from Johnny Iuzzini):
140 g cold butter
150 g sugar
pinch of salt
1 egg white
310 g flour
50 g cocoa powder
4 g baking powder
for the dark chocolate mousse:
3 egg yolks
85 ml simple syrup (cooked out of 90 g sugar and 90 ml water)
150 g dark chocolate minimum 60%
300 ml heavy cream
for the caramelised banana mousse:
probably enough for 8 tartelettes
200 g very ripe bananas
50 g cane sugar
20 g butter
50 ml rum + 1 tablespoon
1 gelatine sheet
1 egg white
25 g sugar
150 ml heavy cream
for the salted caramelised white chocolate ganache:
200 g caramelised white chocolate
140 g heavy cream
fleur de sel as desired
chopped peanuts and white chocolate for decoration
Cream butter with sugar and salt. Whisk in the egg and the egg white, then add the flour, cocoa powder and baking powder. Knead a dough, flatten and put it in the fridge for at least 1 hour. I have used about half of it, and that made 4 tartelettes, you can easily freeze the rest of the pastry. Blind bake the tart shells at 180°C in 10 cm diameter tartelette rings for about 10 minutes.
For the mousse melt chocolate over steam, beat egg yolks with simple syrup in water bath, so that half of the bowl is covered with water, beat until thick and creamy. Remove and beat until it cooles. Stir molten chocolate to the beaten egg yolks and fold in beaten cream. Pour into a plastic bag and chill for 2 hours.
Peel and chop bananas about 1 cm thick. Melt butter, add cane sugar and let it caramelise. Add sliced banana and stir until it is well coated with caramel, then pour rum over it and cook until reduced. Puree bananas and mash them through a strainer. That is an important step, it is pretty tedious but defintely worth the effort. Warm the leftover one teaspoon rum and dissolve the previously soaked gelatine sheet in it and whisk it to the puree. Bring sugar with one teaspoon of water to the boil and as soon as it has reached 120°C pour it to the halfly beaten egg white and keep on beating until it form stiff peaks. Fold beaten egg white and beaten cream into the banana puree. Pour mousse into a bag and chill for 2 hours.
For the ganache bring cream to the boil and pour it over the caramelised white chocolate and stir until dissolved. Season with fleur de sel. If you want that the ganache is less liquid stir in 2-3 tablespoons of soft butter (it will set without butter also very nicely, but for that you gotta leave it in the fridge over night, and i had no time for that now). Divide ganache between the 4 tartelettes shells and chill for 2 hours. After that you can play with the two mousses and fill the tartelettes shells. Decorate with chopped peanuts and white chocolate. It is worth to chill the finished tartelettes over night so that the flavours can develop.