Boston Cream Pie In A Glass
Found on supercocktail.com (i haven't tried this one yet - so i assume you really need to shake hard to combine the cocoa so it won't clump- otherwise maybe that is only for the rim - it isn't written that way though!)!
Steps
Add all ingredients to a cocktail shaker half-filled with ice cubes , in equal parts.
Shake vigorously.
Pour into a margarita or large martini glass with a cocoa dipped rim , and serve.
Ingredients
vanilla vodka, chocolate liqueur, irish cream, cocoa powder