can the ctrockpot cookie be made in a 4qt round or 5qt oval crockpot??

Since the recipe was developed in a 6-quart slow cooker, I can't guarantee another size will work (it's like using a larger/smaller baking dish for a recipe that says "use an 8-inch cake pan" etc); however you can try it using a bit less of the batter, the cook time will likely also shift a bit.