You trained your cat to cry for treats! Your cat is a smart animal and you were rewarding the crying behavior with a treat. Of course that will make it cry more, kitties like treats!

Now you must never give that kitty a treat just because it cried. I give my cat a treat but he must earn it. You need to teach the kitty to work for the food. You can reward the cat for being quiet and not crying, or you can ask it to perform a small task. Standing for food is pretty easy because you can use the food a a lure to make the cat stand, and then when it does, you give it food. That way you are substituting a less annoying behavior for the crying.
Good luck and BE CONSISTANT!