The account you have given of your reaction to his 8/10 comment was, in my opinion, a total overreaction on your part. I don't personally see anything wrong with an 8/10 comment I would have taken it as a compliment and like to think I am a good cook.
But, I am thinking that your overreaction may have come from either the tone in which he said it or related to your comment on the thread that you feel underappreciated.
I think that his reaction has also been totally over the top and exceedingly childish. I couldn't possibly have put up with a week's sulking. It seems such a minor thing on paper to have had this reaction to.
From what you have said about your texts earlier on you both sound like you are being stubborn and determined to have the last word. You have a dig at him to stop sulking, he responds by saying he'll sulk as long as he likes, then you mention correctly his over the top reaction.
What I am saying is that you are both responding to each other in a way that is fuelling the argument. Neither of you are letting it go. If you make reference to him sulking that is the surest way of ensuring he will continue to sulk.
One of you needs to be the adult and actually initiate a calm, face to face conversation where you both hopefully accept that you could have behaved better and apologise. Life is too short to be wasting a week of it on something so minor.
If it is slightly more involved than that, and it does come across that way from one or two things you have said, you need to address those issues with him. Such as feeling underappreciated and what he could do to make you feel more appreciated, help more etc. Otherwise you are just going to continue to get niggles like this.
Wishing you all the best in sorting this out with him.