Combine graham cracker crumbs, melted butter, sugar, and cinnamon in a bowl and mix well. Pat this mixture on the bottom of a 9-or 10-inch springform pan. Set aside. Melt the chocolate in a double boiler. Whip the cream in a large mixing bowl until thick. Combine the warm water and gelatin and mix so there are no lumps, adding more water, if necessary, until consistency of maple syrup. Mix the melted chocolate, slightly cooled but still pourable, the liqueur, and gelatin together. Fold in the whipped cream until well blended. Pour this mixture into the springform pan – tap to make sure it settles – then refrigerate for 2 hours before serving.