In a double boiler, or metal bowl that fits over a pot of boiling water, place cream and milk; add dark chocolate. Stir until chocolate melts into a smooth mixture.
Add the liqueurs and cook until mixture begins to boil. Remove from heat and portion into individual serving bowls.
Refrigerate for a minimum of 2 hours.
To garnish, cut pound cake into croutons and toast in the oven. Top the soup with croutons, white chocolate shavings, and a dollop of whipped cream.