Bring the cream to a boil in a saucepan. Chop the chocolate then pour the cream over top. Let stand for 1-2 minutes then stir until smooth. Stir in the Amaretto.
Let the mousse cool slightly then chill for about 2 hours in the refrigerator.
Remove the mousse from the refrigerator and whip until light and airy.
Distribute the mousse among serving bowls and dust with powdered sugar. Garnish with mint and chocolate shavings, if desired.