One quick-witted Girl Scout and her mother recently uncovered the "Hazy Grail" of cookie sales.

Danielle Lei, 13, sold 177 boxes of Girl Scout cookies outside the Green Cross medical marijuana dispensary in San Francisco on Presidents Day, with customers snagging all her dulce de leches and most of her tagalongs in just two hours. Her mother, Carol, told Mashable that during the same two-hour time window day after her sale at the clinic, her daughter sold 37 fewer boxes of cookies outside a Safeway store.

On its Facebook account, the Green Cross recognized the efforts of the industrious young lady, posting a photo of her table outside of the pharmacy that day.

“It’s no secret that cannabis is a powerful appetite stimulant, so we knew this would be a very beneficial endeavor for the girls,” Holli Bert, a staff member at the Green Cross, told Mashable. “It’s all about location, and what better place to sell Girl Scout cookies than outside a medical cannabis collective?”

And luckily for Green Cross patients who missed out, the sale wasn't a one-day event. Michelle returned to her prized location on Saturday – probably cashing in again on the inevitable munchies of her target demo.