Yes, you can deduct the part of the sales that benefits the Boy Scouts. Popcorn does not typically cost $35!!
You can check the percentage that is deductible by googling, for example, "how much of the boy scout popcorn sale is tax deductible by the customer?" or something to that effect. Be sure you are looking at the correct year and that it is a legitimate site. It may be that the Boy Scout website might provide this info as well
~