M.S.
Hi B.,
I haven't read all the postings but I agree with one of the ladies who said to use the cheapest brownie mix (i.e. Walmart or Kroger brand) or when the brand name ones are one sale for like a buck I stock up!! Then, they key is don't over-bake them. If the box says 28 mins. for a 9x13 I always do 2-3 mins. under that. And I, too, always add mix-ins! I use chocolate chips, white/chocolate swirls, peanut butter/choc. swirls, Hershey's syrup, whatever you want! And if you want thick, cakier brownies try making two boxes at a time in one 9x13 pan. We like them fudgy so I don't do that but my sister in law does. And everyone loves my brownies and can't believe I use the store brand! LOL!!
good luck and let us know what happens!