Levain Bakery has turned into Alex's Lemonade Cookie Stand.
All proceeds from lemon cookie sales go to that foundation, which supports cancer research for children.
Tuesday's fundraiser benefits 4-year-old Riley Cadiz of Park Ridge.
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She's been battling leukemia for two years.
Customers are welcome to come out and support Cadiz from 8 a.m. to 11 p.m. at 840 W. Randolph St.
"I just wanted to try the new flavor, but I didn't know it was a cause behind it. That's very good," customer Angelique Hawkins said.
The Cadiz family was there Tuesday afternoon to sing happy birthday to the little girl and enjoy a birthday cookie cake.
Darcy Jusich helped connect Levain to the organization. She was inspired by the daughter of her close friends, Cadiz.
"Riley is such a bright light. She is so funny. She's fierce because she truly is a warrior," Jusich said.
The bakery was happy to take part in the one-day fundraiser, selling lemon cookies for $5 each. They were flying off the shelves.
"I saw it was for charity, and so I thought it would be a great cause. And, instead of buying one, I got two," Billy Loggarakis said.
Cadiz's parents thanked everyone, and are hoping, with others' help, the girl will win her battle against cancer.
"People who help others get through tough times like this help us see the light and the humanity of things, and makes us more gracious and humble," one family member said.
Levain has partnered with Alex's Lemonade Stand before during events at their New York and Los Angeles locations.
Even though the fundraiser ends Tuesday night, the lemon cookies will be around until the end of June.
Visit www.alexslemonade.org for more information.