I found this on Recipezaar, posted by CountryLady - it's so good, I had to share.
The Snowy Boulevard
3/4 ounce vanilla vodka (plain plus a shot of vanilla extract works just fine)
3/4 ounce coffee liqueur (I used Kahlua)
6 ounces hot cocoa
Homemade marshmallows or whipped cream
Put vodka and liqueur into a heatproof mug. Add hot cocoa and stir. Top with a homemade marshmallow or whipped cream.
After two of these, my destination is a good night's sleep.