Boston Cream Pie

1 1/2 oz vanilla vodka
1 1/2 oz chocolate liqueur
1 1/2 oz Irish cream
1 1/2 oz Powdered cocoa

Add all ingredients to a cocktail shaker half-filled with ice cubes, in equal parts. Shake vigorously. Pour into a margarita or large cocktail glass with a cocoa dipped rim, and serve.