Blend speculoos cookies in a blender or food processor until the crumbs have reached the desired consistency. Continue blending cookies until you have 2 cups of crumbs.
Over low heat, add butter to a small saucepan. Once melted, stir in sweetened condensed milk and evaporated milk.
Slowly pour in the liquid to the cookie butter crumbs until the cookie butter has reached a moist consistency. You may have extra liquid left over at this point.
Once the cookie butter is well stirred, refrigerate it for at least one to two hours or until it has thickened. If the cookie butter is too thick, stir in a little bit of milk or water. Serve with your favorite dippers!
Cookie butter can be stored in the fridge for up to one week.