Mind Eraser

 1 1/2 oz. Kahlúa
1 1/2 oz. vodka
1 1/2 oz. Sprite, or 7-up

Fill a rocks glass with ice. Add the Kahlúa first, then slowly pour in the vodka, and then the top it off with Sprite. (The key is to try to keep it layered.) Use two straws to suck it all down at once.

Makes 1 cocktail.