Rim a shot glass with sugar. Slice a lemon. Fill the shot glass 3/4 of the way with vanilla (or regular) vodka, float a 1/4 shot of Frangelico on top. Take the shot, making sure you get some sugar as you slurp, then immediately suck on the lemon. mmm It'll taste like chocolate cake!
It's good in coffee and hot chocolate as well. Or make a White Russian and float some on top of the Kahlua before you add the cream for a little twist. Probably could even skip the Kahlua and just use the Frangelico.