Line cookie sheet with tinfoil and coat with cooking spray. 

Mix ingredients in large bowl with fork or potato masher. (You can mix with your hands as well. If so, I highly suggest removing rings first.) 

Using a 1 oz (#40) scoop, gather a portion of the gluten-free meatball mixture. Drop in the palm of your hands and roll into a ball.

Bake gluten-free meatballs in the oven, one sheet at a time, at 350 for 15 minutes. I highly suggest flipping them after 7 minutes.

Remove baked meatballs from cookie sheet and place in crockpot or dish with lid. Repeat until all meatballs are cooked.

In a medium sauce pan, combine ketchup, grape jelly and barbecue sauce. (The barbecue sauce is optional, but I highly suggest it to cut the sweetness of the sauce.) Cook until jelly melts completely. Allow to cool. 

Finally, layer cooked meatballs and sauce in slow cooker. Cook on low heat for at least 4 hours. Stir occasionally so sauce does not burn.