Investigators say anyone who wanted to buy the drugs simply pulled up to the drive-thru, ordered a Happy Meal, and then used the secret code "boy's toy."
Police say 26-year-old Shantia Dennis, who worked at a McDonald's in the East Liberty neighborhood of Pittsburgh, sold Happy Meals for $82. She allegedly put $2 in the cash register for the toy and then stuffed the rest of the cash inside her bra.
Officials were tipped off by an informant, and Dennis was caught selling the drugs to undercover officers on Wednesday afternoon. Detectives found an additional $80 hidden in Dennis' bra, as well as a small amount of marijuana.
Dennis is being held on $30,000 bail. She has a preliminary hearing on Feb. 11.
ABC News contributed to this report.