This recipe works best if you drain as much liquid as possible from the spent grain. Consider lining your strainer with cheesecloth to really squeeze it dry.
If you own a dehydrator, you can move the cookies to it after baking for a long, slow crisping time.
Preheat oven to 350º
OPTIONAL: Use a fork to mark lines, which makes it easier to break off the cookies when finished.
Bake for 30 minutes or until starting to brown around the edges.
Once it starts to brown, you can either pop the cookies out to distribute onto a few trays in your dehydrator, or turn your oven down to the lowest setting and continue baking until crisp. This takes 4 to 8 hours depending on moisture content.
Find it online: https://www.rover.com/blog/brewers-spent-grain-dog-treats/