Sieve the powdered sugar

Squeeze a 100 ml of juice out of the lemons and mix it with the powdered sugar

Add the limoncello to the mixture

Mix the whipped cream with the crème fraîche and whip it

Add the lemon mixture to the whipped cream and stirr it

Cut the mango into very tiny pieces (tinier than in my picture, otherwise the pieces of mango become difficult to eat) and mix them with the rest

Put it in the freezer and stirr it every half an hour for the next four hours