You use a family size box of Betty Crocker brownie mix, plain or with walnuts.
Use 3 big (about 6 oz.) Hershey bars, I use one Symphony, one regular, and one almond. Spread half of the batter on the bottom, place the 3 candy bars whole on the batter, then top with the other half of the batter. You can go to Foodnetwork.com and look up Symphony Brownies if you would like also.