We had problems with this. Could be the ingredients weren't chilled or my amounts was off but the fudge did not thicken. Good thing I used double bags because the seal burst (I hate cheap plastic bags). It did keep the teenagers busy while driving and they didn't mind eating the chocolate goo!
The only thing I did differently was to add 1/4 t. vanilla to the bag. The kids loved it. I used my cookie scooper and got about 23 - 24 scoops per bag. Thanks for posting. 8-)