Dude...your pokemon won't eat any more poffin no matter what you do. I hate saying this but your Monferno will never be able to have max coolness =( you'll have to get a new one and try again.
You just have to make sure you bake better poffin next time. Avoid letting it overflow and make sure you stir it quickly enough so that it doesn't get stuck to the pan. The general idea is to stir it as quickly as possible without it overflowing. When the flames go blue it's thicker and you don't have to worry about it overflowing anymore so you can stir as quickly as you like and it will never overflow =)
It has to be high level with low smoothness. High level means that the coolness is raised more, and low smoothness means that your pokemon's sheen isn't taken up too much. You have to be very careful with your sheen.
To make good poffin I think it's much better if you bake it with more than one person. Do you have anyone you can bake poffin with?
If you're making poffin with other people make sure you DON'T use the same berry or you'll end up with "Foul Poffin"
