Instead of listening to a lecture about the Scientific Method, at the beginning of class the 7th and 9th grade girls were given an envelope containing clues to help them solve a number of puzzles and riddles. The answers eventually allowed them to decipher the combination of the lock securing a large treasure chest. Munchkin donut holes were the surprise at the end.
The girls had a blast, and since the clues were all key concepts of the Scientific Method, they could connect with it better. (They also learned intellectual humility when their hunches were wrong.)