This 43-Year-Old Started a Side Hustle at a Farmer's Market — Then She Quit Her Job and Built an 8-Figure Brand Sold in Costco Hannah Barnstable, CEO and co-founder of Seven Sundays, was inspired to start her business while on her honeymoon in New Zealand.

This Side Hustle Spotlight Q&A features Hannah Barnstable, CEO and co-founder of Seven Sundays, a certified B Corp nutritionally dense cereal brand available nationwide. Seven Sundays is an eight-figure brand that's more than doubled its growth for three consecutive years, expanding into 2,000 new stores, including Costco and Sam's Club. Responses have been edited for length and clarity.

^{Image Credit: Courtesy of Seven Sundays. Hannah Barnstable.}

What was your day job or primary occupation when you started your side hustle?
Before founding Seven Sundays, I worked in finance, specializing in investment banking for food companies. This career gave me a front-row seat to the complexities of the food industry, as I worked closely with founders and family businesses. It also allowed me to develop a deeper understanding of the financial challenges food companies face while trying to create positive change.

When did you start your side hustle, and where did you find the inspiration for it?
Seven Sundays officially started in 2011, but the inspiration began earlier, during a backcountry road trip through New Zealand with my husband on our honeymoon. At that time, we were working our butts off in New York City, and we were burnt out from our demanding jobs. As we traveled, we were struck by how clean, sustainable food was so heavily embedded in the locals' everyday lives. Each morning, we enjoyed a bowl of muesli, a breakfast staple in New Zealand, and those breakfasts sparked long conversations about our future. When we returned home, we realized we couldn't find anything like the muesli we had in New Zealand. The cereal aisle in the U.S. offered little in terms of real ingredients and wholesome, convenient cereal options. So, I began experimenting in the kitchen creating my own recipes.

My background in investment banking for food businesses also shaped my decision to start my own company. I had worked with many inspiring entrepreneurs and family-run companies, and their all-in approach really resonated with me. That experience, paired with my desire to create better food for my own family, motivated me to take the leap in 2011 and launch Seven Sundays.

What were some of the first steps you took to get your side hustle off the ground?
One of the first steps was actually quitting my finance job and moving from Manhattan back to Minneapolis. It was a huge change — from investment banking to selling homemade muesli at a farmer's market. I started small with just a bike, a small farmer's market stall and a handful of recipes I made after hours at a friend's restaurant. Selling jars of my muesli at a local farmer's market was a hands-on way to test the product and see how people responded to this healthier, less processed cereal.

^{Image Credit: Courtesy of Seven Sundays}

For the first couple of years, I focused on taking a step back and learning the intricacies of the food industry, which I'd seen lead to a "race to the bottom." So, I decided to do things differently from the start. Although my business first started with muesli, I knew that it was not going to be at the forefront of breakfast choices in the U.S. as it was in New Zealand. So, I continued to focus on innovation, quality, real ingredients and sustainability, even when it was challenging, and expanded into creating more breakfast foods, like cereals and protein oatmeal with upcycled food.

What were some of the biggest challenges you faced while building your side hustle, and how did you navigate them?
Building Seven Sundays while starting a family was one of the most challenging yet rewarding aspects of my journey. I launched the company while pregnant and adjusting to motherhood. Balancing both was not easy, but it gave me a deeply rooted motivation to reshape the breakfast aisle and provide real food for future generations. This passion fuels our mission to reimagine the food system from the ground up, creating cereals that enhance both personal health and the well-being of our planet.

Another big challenge was convincing the conventional, male-dominated food industry to embrace my vision of a product with only 100% real ingredients without relying on labs or flavor houses. When I started, "better-for-you" cereals weren't mainstream, and many of my ideas were considered ahead of their time. But I stuck to my vision, and over time, we expanded beyond muesli and introduced our Sunflower Cereal, made from upcycled ingredients. The journey from niche muesli to an innovative cereal brand was a leap of faith, but embracing that challenge and our core values of providing clean, delicious food helped us grow.

^{Image Credit: Courtesy of Seven Sundays}

What has growth and revenue looked like?
Today, Seven Sundays is an eight-figure brand. The company saw consistent monthly revenue right away and roughly 100% year-over-year revenue growth. The side hustle was necessary because it took almost eight years for the business to become profitable and self-sustaining.

After two years of selling our upcycled cereals, Seven Sundays became the No. 2 cereal brand at a major natural grocery chain and is the leading contributor to cereal growth within the natural grocery channel. We are in our third consecutive year of more than doubling revenues.

We've also expanded into new stores, including Costco and Sam's Club, and we're now available in over 5,000 locations nationwide.

What do you enjoy most about running this business?
One of the things I love most is having my family so deeply involved in the business. My kids are my best — and most honest — taste-testers. I throw whatever we have developed on the table. Their feedback is always the first I seek when developing a new product, and having them involved reminds me why I started this journey.

The customer feedback we receive is also a huge source of joy for me. Knowing that we are providing families with better-for-you, nostalgic foods makes everything worth it. Many of our consumers had given up on the cereal aisle altogether before discovering Seven Sundays. It motivates me to keep pushing the boundaries and find new, innovative ways to improve the cereal aisle.

What's your advice for others hoping to start successful side hustles or full-time businesses of their own?
Think outside the box. There are endless challenges in building a startup, particularly in the food industry. I always remind myself, If it were easy, everyone would do it. Margins are slim, and there are many layers (brokers, distributors, retailers) to the traditional system. For the first few years, I learned the ropes and eventually realized that following the typical playbook of building a food business wasn't going to work for me. I decided to do everything differently: focus on improving people and planet health — a mission bigger than the bottom line.

Don't be afraid of change. For a long time, I resisted branching outside of muesli (even though I knew deep down I had to). But I realized Seven Sundays could stay true to its core values and innovate for the ever-changing consumer. For me, this meant creating at the intersection of people and planet health using upcycled ingredients and providing gluten-free and grain-free options, all while using real food only and always nailing that nostalgic taste we are known for.

^{Image Credit: Courtesy of Seven Sundays}

Lean into your mission. Alongside building Seven Sundays, I welcomed three kids over the past 12 years. Involving them in the business has certainly added challenges. There will be times when you want to give up — that's inevitable. But having a strong mission to ground you will make all the difference. For me, that mission is creating better food for future generations. My kids remind me of that mission every day, and they've become an integral part of our product development process, helping keep our focus where it belongs: on making the food system better, one bowl of cereal at a time!

Lastly, grit and patience are crucial. You won't fail unless you quit. It's important to view your venture as a long-term commitment — at least five to 10 years — because building something meaningful takes time, care and dedication.