"The Toffee-tastic is a bleak, flavorless, gluten free wasteland," Charlotte McCourt wrote in the letter to a family friend. "I'm telling you, it's as flavorless as dirt."
The sixth grader was encouraged by her parents to write the letter after she became concerned that only a couple of boxes she had sold were to be donated to U.S. military troops.
In an effort to boost that number, she rated each of the Girl Scout cookies on a scale of 1 to 10.
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The popular Thin Mint earned a "9" for its "inspired" combination of chocolate and mint, while the Do-si-dos peanut butter sandwich cookie earned a "5" for "its unoriginality and its blandness."
"If you have a wild sense of adventure, try the S'mores," Charlotte wrote. "Full disclosure, I have not tried the S'mores so I cannot rate it in good conscience."
The letter later went global when former "Dirty Jobs" star, Mike Rowe, read it in a video posted on his Facebook page.
Charlotte's dad is a producer and writer on Rowe's podcast, "The Way I Heard It," according to ABC News.
Anyone can donate cookies to the troops through Charlotte's cookie ordering website.
Read the full story from ABC News
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