Chill your tools: Pop your serving glasses in the freezer for 10 minutes.
Cold glasses keep the shake thick longer.
Prep the Oreos: Set aside 1 cookie for garnish if you like. Break the rest into chunks so they blend evenly.
Blend the base: In a blender, add cold milk, ice cubes, milk powder or condensed milk, vanilla, and a tiny pinch of salt. Blend on high until smooth and frosty.
Add cookies: Drop in the Oreo chunks.
Pulse 4–6 times for a chunkier shake or blend fully for a smooth texture.
Adjust sweetness and texture: Taste. If you want it sweeter, add sugar or honey. For extra creaminess, blend in the butter or oil now.
If it’s too thick, splash in more milk. Too thin? Add 1–2 more Oreos or a few ice cubes and blend again.
Serve immediately: Pour into your chilled glasses.
Top with whipped cream and crumble the reserved Oreo over the top if you like.
Enjoy: Add a straw or spoon and drink right away while it’s cold and creamy.