Heat the whipped cream and nougat cream in a saucepan, stirring, until the nougat cream has completely dissolved into the whipped cream. Remove from heat and leave to cool for at least 3 hours.
Finely chop 1 tbsp candied ginger. Whip the completely cooled nut nougat cream with the whisks of the mixer until stiff and fold in the diced ginger. In a mold, alternately layer wafer rolls and mousse on top of each other. Dust the charlotte with cocoa and garnish with the remaining ginger cut into strips.
Finally, decorate with the wafer rolls.