Coat the rim (optional)

1. Remove the creme from the Oreos and discard (or eat). Place the cookies in a plastic bag. Then, crush them into a powder using a rolling pin or a heavy glass. Pour the Oreo powder into a shallow saucer that is big enough to fit the rim of your glass. Then, pour 1 ounce of chocolate liqueur or simple syrup into another saucer.
2. Carefully dip the rim of the martini glass in the simple syrup or chocolate liqueur. Leave it upside down, hovering over the dish for a few seconds to allow any excess liquid to drip off.
3. Then, dip the rim into the dish of Oreo crumbs, gently rotating it until it is fully coated in cookie crumbs.

Make the martini

1. Fill a martini shaker half full of ice. Then, add the vodka, chocolate liqueur, creme de cacao, and heavy cream. Close the lid and shake vigorously to mix and chill the martini.
2. Strain into a prepared martini glass or coupe glass and serve immediately.