Reserve two Oreo halves for garnish and coarsely crush the remaining 6 Oreos by hand or in a zip-top bag with a rolling pin (leave some larger chunks for texture).

Make chocolate drizzle

Pour 1 tablespoon of chocolate syrup around the inside of the chilled glass, letting it stream down the sides to create a decorative drizzle. Set the glass aside.

Blend the shake

Combine ingredients

In a blender add 1 cup whole milk, 2 cups vanilla ice cream, 2 tablespoons malted milk powder, 1 teaspoon granulated sugar, 1/2 teaspoon vanilla extract, the coarsely crushed 6 Oreos, and the optional 1/2 cup crushed ice (if using for thicker texture).

Pulse and check texture

Pulse the blender 6–8 times until mixed and smooth but still slightly chunky from Oreo bits. If too thick, add up to 2 tablespoons more milk; if too thin, add a few spoonfuls more ice cream and pulse again.

Assemble & finish

Pour the blended shake into the prepared glass. Spoon the remaining 1 tablespoon chocolate syrup over the top or around the inside rim if desired.

Top with 1/2 cup whipped cream, place the reserved Oreo halves on the whipped cream as garnish, and lightly dust with 1/2 teaspoon malted milk powder for an extra malted aroma (optional).

Serve immediately with a wide straw and a long spoon.