Mix ingredients until smooth. Different brands of mix may call for varying amounts of water but start with 1/4 cup, adding more if needed, 1 teaspoonful at a time. The batter should be very thick.
After mixing thoroughly, spoon the batter into a greased 9x13 inch pan. Smoothing it out evenly with Pam sprayed hands. Bake at 350 degrees for 20 to 25 minutes for a chewy brownie, a little longer for a drier, cake type.