The recipe came from this website: https://byo.com/stories/issue/item/2368-grains-to-treats-last-call. Clearly his look better, but my dog loves the ones I made and that's all that matters to me. I am copying the recipe below for the sake of easy reference for myself. My recipe makes 50% more than the recipe in the link. I did this, because I could only find Peanut Butter in 12 oz. bottles or larger and I wanted to use the whole jar.
Spent Grain Dog Treats
6 c. Spent Grain
12 oz. Smooth Peanut Butter
3 c. Flour
Mix all the ingredients together and smooth onto a Silpat. Score into rectangles about 1" x 2". Bake at 350 for 30 minutes and then at 225 for 2 hours, or until they are completely dry. Snap the treats apart and store in the freezer. I don't thaw them before feeding them to my dog.