Here's a comment I made on FB when someone asked. I will try to get an exact recipe next time.
I make veggie and oat dog treats a lot. I use either carrots or broccoli as the vegetable
Throw the veggies in a food processor and blend until it's as small as it will get. You can add a little water (I do this with broccoli, carrots normally don't need it) to help.
Then add some oats! About a cup or so, depending on how much veggies you added. Pulse just a little to help it get mixed up.
Pour into a mixing bowl. If it's super wet, add more oats. You want to add just enough flour to hold it together and make it doughy. So if it needs to dry up a lot, use oats. They're healthier than pouring in a lot of flour.
Once you have your oats and flour all mixed it, just make balls in you hands and flatten them into little discs! Put on a lightly greased (I use just a teeny bit of cooking spray) pan and bake at 350 for around 20 min. Flip half way through.
Before I got my food processor, I would steam the veggies until really soft and mash them like I was making mashed potatoes. Takes a lot more effort but gets the job done!
Sometimes I add peanut butter. I always throw in some flax if I have any on hand.
I'll measure next time so I can tell you exactly what amounts I add. I normally just eye ball it.