Into a blender add vanilla ice cream, chunky or smooth peanut butter, peanut butter breakfast cereal, Girl Scout Do-si-dos cookies, and two tablespoons of heavy cream or whole milk. Secure the lid and give it a good blend for a minute.

Remove the lid and check the consistency, you can add heavy cream or whole milk a tablespoon at a time to get the thickness and creaminess you want. I like my shakes on the thick side, so I didn't add as much heavy cream.

Prepare the serving glass by scooping peanut butter on the bottom of a tablespoon and smearing it along the inside of the glass.

Spoon the Peanut Butter Breakfast Cereal Cookie Shake into the serving glass and drink it with a straw or scoop out the yumminess with a long-handled parfait spoon.