3¾c. of brownie mix (again, Betty Crocker Original Supreme)
2 eggs
¼c. water
⅓c. vegetable oil
and the included packet of Hershey's syrup
The baking times on the old box were: for 13x9 pan, 28-30m at 350°, for 9x9 pan, 35-40m at 350°, and for 8x8 pan, 50-55m at 325°. (We usually use the 13x9, can't speak as much to the other sizes.)
As of the original redesign mentioned in the story, the amount of brownie mix in a box was cut back to 3 cups, the recipe involved 1 egg instead of 2, and I don't remember how the water and oil were affected but they were different.