Slowly melt the chocolate in the top of a double boiler along with the cream, over medium heat.
Remove from heat and mix until combined. and continue stirring until it is relatively cool. Allow to sit until it is cool enough to put into the refrigerator. Remove bean and refrigerate overnight.
Melt the chocolate again in a double boiler. When it is completely melted, mix in the butter until it is absorbed. Stir regularly until starting to cool. Then whip, with a very slow electric mixer, until the butter is completely absorbed and chocolate is cooled. Refrigerate for a few hours or overnight.
Heat once again and add vanilla bean and coffee liqueur and stir occasionally until it is cool. Remove bean and whip in an electric mixer until cool. Refrigerate until it is thick enough to pipe through a pastry bag.
Using a 1/2″ tip, make little balls on a sheet of parchment paper that has cocoa powder spread on it. Roll in the powder. Keep chilled until just before serving. Let them return to room temperature before serving.