This is a little complicated and subtle, so this is not a drink to be bought on the fifth or sixth round. Try it early in the night,and don't be stingy, the ladies love these. This drink is a ritual shooter, akin to a Ritual Tequila.
You'll need vanilla vodka, a hazelnut liqueor like Frangelico, sugar, and a lemon wedge.
First things first, take a shot glass and line the rim with sugar. Then take the lemon wedge and coat it in sugar. Next, take one part vanilla vodka and one part hazelnut liqueor and stir them together and pour into the shot glass. Now the drink is prepared.
Unlike the other cocktails I've written about here, this drink needs to be drunk an a particular fashion. First down the shot. It will taste like ass. Next bite into the lemon wedge and suck on it. That aftertaste of ass will suddenly be transformed into the taste of chocolate cake, and if you really buy into it, it almost feels like you're biting into a big piece of chocolate cake.
There really aren't any ways to change it up. Some people proscribe orange vodka instead of vanilla... they are idiots, vanilla's the way to go.