Preheat the oven to 175°C / 350°F and line a baking tray.

Rub 60 g unsalted butter into 60 g all-purpose flour, 20 g cocoa powder, and 40 g brown sugar.

Spread the chocolate streusel on the tray and bake until crisp, about 15 minutes.

Melt 100 g dark chocolate and combine it with a small amount of lime syrup to make a smooth chocolate gel.

Slice 400 g bananas and caramelize them in a frying pan with salted butter caramel.

Brush both sides of the vanilla ladyfingers with 120 ml lime syrup.

Line the base and sides of the charlotte mold with the soaked vanilla ladyfingers.

Whip 300 ml heavy cream with 50 g powdered sugar and 10 ml vanilla extract until firm peaks form.

Fold half of the vanilla whipped cream into 300 g vanilla candy cream.

Spread half of the vanilla cream into the lined mold and add the caramelized bananas.

Add a layer of salted butter caramel and cover it with the remaining vanilla cream.

Seal the charlotte with remaining ladyfingers and chill for at least 60 minutes.

Unmold the chilled charlotte and pipe or spoon the remaining vanilla whipped cream on top.

Finish with chocolate gel, chocolate streusel, and extra salted butter caramel before serving.