2) Combine the eggs and vanilla and beat together in a bowl. Add a tbsp of the chocolate mixture to the eggs and beat well. Slowly stir the entire egg mixture into the chocolate mixture. Whisk the hot chocolate briskly in the double boiler for three minutes.
3) Divide the white chocolate liqueur or creme de cacao between the mugs. For a peppermint flavour, add the schnapps. Top up with the hot chocolate mixture and serve immediately.