Crust: Combine the crumbs sugar and melted butter. Press firmly and evenly into a 9-inch springform pan. Place in refrigerator while making filling.
Filling: Melt chocolate in heavy saucepan. Beat cream cheese and sugar until smooth. Add sour cream. Blend well. Beat in eggs one at a time beating at low speed. Blend in bourbon and creme de menthe. Pour 1 1/4 cups batter into another bowl. Mix remaining batter with the melted chocolate. Fill crust with the chocolate batter then slowly pour on the plain batter making a swirling pattern as desired. Bake at 350 degrees F for 45 to 50 minutes. The sides will be puffed and the center will be soft (it will firm when cooled). Chill at least 6 hours before serving.
NOTE: An extra dash of creme de menthe may be added to the plain batter.
Source: E-Cookbooks.net