In a chilled bowl, whip together the heavy cream and mascarpone until soft peaks form, about 3-5 minutes. Gradually sprinkle in the powdered sugar, continuing to whip until combined.

Soak the gelatin sheets in cold water for about 5 minutes. Meanwhile, heat the coconut milk until warm but not boiling, then dissolve the gelatin in the warm milk.

Once cooled slightly, gently fold the coconut milk mixture into the whipped cream until combined.

Pour the mousse mixture into hemisphere molds, add a dollop of chocolate spread, cover with more mousse, and freeze for at least 6 hours.

Mix the shortbread ingredients into a soft dough, chill, roll out, cut into rounds, and bake at 180°C (350°F) for about 10 minutes.

After the shortbreads cool, remove the mousse from molds and place each dome on a shortbread base, allowing to thaw for about 2 hours.

Before serving, sprinkle each dome with grated coconut for garnish.