Start by breaking the Biscoff cookies into smaller pieces for easier blending.
Place the broken cookies into the food processor and pulse until they turn into fine crumbs.
Add the powdered sugar to the cookie crumbs and pulse until well incorporated.
Slowly add the evaporated milk while the food processor runs to create a smooth texture.
Sprinkle in the ground cinnamon and pulse until completely smooth. Adjust consistency with more milk if needed.
Taste and adjust sweetness or spice level as necessary.
Transfer the cookie butter into a clean jar or container and store in the refrigerator.
