In a saucepan, melt together the butter, sugar, ice cream, and baking chocolate until smooth. Whisk in the water and orange flavoring. Heat over medium-high heat, just until steaming. Serve with whipped cream and a sprinkling of orange zest and grated chocolate in chocolate-dipped shot glasses.
To chocolate-coat the edges of your shot glasses, zap 1/4 cup semi-sweet chocolate chips in a small, microwave-safe bowl just until melted. (The chocolate should be smooth and melty, but not hot. Overheating it wil cause the chocolate to mottle as it cools and hardens, so be careful that you only just microwave it until it's barely melted.) Dip the edges of each shot glass into the melted chocolate. Allow the chocolate to cool and harden before pouring hot cocoa into the glasses.