But, I would get headaches when I was
eating fat free things with these food additives in it or
sugar substitutes just a few hours later. To be honest, I would not think two days later, that the migraine is associated with the cookie.
If you do suspect it though, then it's easy enough to look at your diet and avoid such things that have ingredients like the cookie. Eliminating the things I am sensitive to has all but stopped any migraines with one once a year now at most.