No one really answered the Brownie question so I will give my opinion.
The brownies were to me really bad. I personally think it had to do with the cinnamon in the mix. Also I haven't tried to make anything else but if you aren't really careful the ingredients shift during travel and it isn't as pretty as you would think.
At the fair I would have several different mixes to show what they look like. Then have a "sale" on the sm. batter bowls if they buy so many. You can reduce the price and give them the directions on how to make them. Have tags already printed out to give to the people who buy the bowls. Then place and order for it. Your other option may be to have preorders at the fair and tell them when you expect them to be in and have them come to your house to pick up and make the bowls. That way it feels like less work but you aren't as liable for selling food products. Also you can have another station or two with tools they may not have thought of and maybe get a whole nother show out of it.
Thanks so much for these ideas as I have plenty of fairs to do this season. Northern states have a lot of thier fairs during the summer. Here in Florida it is too hot so most of the fairs we have are during the spring/fall. Great way to get holiday shopping orders.
Thanks
Tiffany