- Pour the cream into a mixing bowl and whip up lightly. Spoonful by spoonful, add the Zùsto. Keep going until the whipped cream is lumpy (don’t whip it up completely yet).
- Squeeze the 2 limes, keeping the juice aside. Grate the peel for the zest.
- In another mixing bowl, pour the mascarpone together with the juice from the 2 limes. Whip the mascarpone loosely with the juice.
- Add the mascarpone batter to the cream and mix again briefly until you have a smooth batter.
- Spoon the batter into glasses (or, using a piping bag, pipe the mousse into the glasses, which works a little better) and top with the zest.
- Store in the fridge.