Roswell residents and High Meadows School students, Maggie Guziel, 10, and her sister Kelsey Guziel, 9, have turned an old-fashioned cookie into a milkshake and they're hoping it does some good locally.

The girls will appear on today's "Better Mornings Atlanta" edition on CBS at 5:15 a.m. to whip up a batch of their Whoopee Shake, a cool treat they invented for Mayfield's "Below Zero Hero" milkshake recipe contest.

"I saw the blurb about the contest in Atlanta Parent Magazine earlier this summer," said the girls mom, Ellen Guziel. "The idea tickled the girls and our family spent the next day brainstorming milkshake ideas." 

The Whoopee Shake was just one of several creative ideas the family came up with; the other ideas included: grasshopper, butterbeer, turtle cheesecake, salted carmel bacon, as well as coffee and donuts.

"We must have had at least 30 to 40 different shake concepts," Ellen said.

According to Ellen, in compliance with contest rules, the girls probably submitted around eight different shake concepts in total. It was the Whoopee Shake that really made an impact on Mayfield judges though.

The special shake got the Guziel girls into the top ten finalist recipes out of thousands of entrants, according to the contest website.

Now, the winner of the contest is left up to voters. 

Mayfield will award $10,000 to the inventor of whichever recipe gets the most votes. But aside from winning the money, the girls hope to do something with their sweet creation to benefit local children in need.

The contest ends tomorrow, Sept. 1. Follow the girls' Twitter account for more updates.