If you mean by cooking that you are heating something that contains aspartame, no, it can't be heated for prolonged periods of time.

Some people avoid Nutrasweet - it's another name for aspartame -like the plague. However this is a personal choice. I don't use it.

If you want to find out more information to come to an educated conlusion, do an internet search. There are pros and cons to the argument. There is also a great article on sweeteners in Low Carb Tips at the top of the page.

Karen