I found this on the Internet. I don't know how current this is. If not, perhaps he could give you an idea where else they are available in the US.

Dan Verkinderen
Dan is the son of the late Henry and Mary(Nuytten) Verkinderen. Henry came over from Belgium in the year 1927 and settled near the city of Ghent, MN. They had four children, Joe, Dan, Jane, and Charlotte. Dan is married to Arlene and they live in Ghent. Make sure you visit the section on wonderful recipes that Arlene has provided. Dan has been making and selling rolle bolles since 1976. He has been making and selling Belgian cookie irons since 1982.

You can contact Dan & Arlene via mail, phone, or email at the following:

Dan & Arlene
207 English St.
Ghent, MN. 56239

PHONE:
507-428-3489

EMAIL ADDRESS:
darco@starpoint.net