In a blender, combine chocolate ice cream, Baileys Irish Cream, milk, vodka (if using), chocolate syrup, and vanilla extract. Blend on medium speed until smooth and creamy.

Taste your cocktail and adjust sweetness or strength as desired, blending briefly to mix any adjustments.

Drizzle chocolate syrup along the inner sides of a tall glass for an elegant presentation.

Pour the blended mixture into the prepared glass, filling it close to the top.

Top generously with whipped cream, allowing it to spill slightly over the edges.

Garnish with crushed Oreos or chocolate shavings, followed by a light dusting of cocoa powder.

Serve immediately, offering guests a straw or spoon for sipping.