Ten years ago, friends Lizann Anderson and Suzie Miller started making mixes in an eight-by-ten-foot kitchen built onto Anderson’s Ann Arbor garage. Now their whole grain, gluten-free creations can be found in more than 6,000 stores nationwide, including Target and Whole Foods.

Their company, Among Friends, started with sales to friends and family. It grew as they developed relationships with Whole Foods and other retailers in Ann Arbor and Toledo, where Miller lives. Anderson says the two initially ran the business “very part-time”; she did freelance writing for a Chicago marketing firm, while Miller was a freelance gardener and housecleaner.

They went full-time in 2012, when they moved Among Friends into a 3,500-square-foot space in the Airport Plaza industrial park. The last few years have brought a series of major developments, thanks to an anonymous angel investment in 2013. Among Friends moved to a 10,000-square-foot Airport Plaza space that year, hired ConAgra and Sara Lee vet Darcy Zbinovec as CEO in 2014, and made a nationwide push into Target, Kroger, and Publix stores last year.

Anderson says she and Miller, who each have three children aged seventeen, nineteen, and twenty-one, had been waiting for the opportunity to grow their business. “We were raising kids, and we didn’t have capital, and we didn’t have access to business resources,” she says.

Anderson and Miller both grew up in Toledo, where their families knew each other, but it took Ann Arbor to bring them together. Miller lived here for several years in the early ’90s while her husband was coaching basketball at EMU. Miller was working at the former Group 243 advertising agency when she had a chance conversation with Anderson’s father, who also worked in marketing. He suggested that she get in touch with his daughter, who had just moved to Ann Arbor.

The two met for the first time at Seva in 1994 while pregnant with their first children. Miller says they “immediately hit it off”–although “[Anderson] was very, very quiet. I thought on the phone, ‘She hates me.’ But she’s just shy. We are definitely polar opposites.”

The two bonded quickly over their love of cooking and nutrition, sharing food and recipes long before they converted a small storage room off Anderson’s east-side garage into what they now jokingly refer to as their original “world headquarters.” From the start, their kids had a major impact on the business. Miller says she was “kind of a weird kid” in that she always preferred whole wheat to white bread–“I used to eat wheat germ out of the jar!” But their own children were quite the opposite, and the women tried with varying degrees of success to ply their kids with health food as they grew up. Anderson says she was inspired when a batch of Miller’s heavily oatmeal-based chocolate chip cookies scored big with her kids. She began experimenting with the recipe.

“I added flax meal and way more oatmeal and whole wheat pastry flour, and then Suzie would taste them, and I’d back off on something and add something else,” she says. “And that was the Suzie Q. That became the original oatmeal cookie mix.”

Suzie Q’s Oatmeal Chocolate Chip Cookie Mix is still part of the Among Friends line, along with seven other mixes named after the founders’ friends and family members. Many, like Shane’s Molasses Ginger Cookie Mix and CJ’s Double Chocolate Cookie Mix, are named after the duo’s children, who have remained the company’s top taste-testers through the years. “I think both of us carry the image of that child in our brain,” Anderson says. “How do we make something that appeals to them? Then we know that we’ve done something.”

Their most recent innovation was to make all Among Friends mixes gluten free. As recently as last summer only about half the product line was gluten free, Miller says, but that “started becoming confusing for the consumer and the retailer.” The founders and Zbinovec jointly decided to make the overhaul.

Although Among Friends’ staff has swollen over the past year to include twenty part-time and full-time employees, Miller and Anderson reformulated the recipes on their own, emphasizing oat flour, almond meal, and brown rice flour. Anderson says they endeavored to avoid the ambiguously named “specialty flour blend” that often turns up on the ingredients lists for other gluten-free products. “There might be some whole grain in there, but usually the bulk of it is potato flour, potato starch, tapioca starch, [or] white rice flour,” she says.

So far the change seems to be paying off. Among Friends has doubled its revenues every year since 2012, expanding from 300 retailers to the current 6,000. Retail sales last year exceeded $3 million, and the company will be expanding its relationship with Target this year (although Anderson and Miller remain contractually coy on details).

Originally developed for people with celiac disease, gluten-free foods are now sought by many other consumers. But Anderson and Miller say they’re not worried about the possibility of the fad fading. Gluten-free, they say, is just one part of their mission to market whole-grain mixes with minimal, nutritious ingredients.

“We wanted to create something that wouldn’t affect health adversely,” Anderson says. “We recognize this is not a vegetable. It’s not kale. It’s not spinach. But you can create treats that have some nutritional content to them.”