When Lisa Carlson and Carrie Summer started slinging their Indian-spiced mini-doughnuts from a trailer a decade ago, there was only one other licensed food truck operating in Minneapolis.

The business partners — who are also a couple — led the charge to make the city friendlier to mobile kitchens like theirs. Downtown lunch in summer would never be the same.

But this coming spring and summer's Mill City Farmers Market may be the last chance to get those addictive doughnuts sprinkled with cardamom, ginger and nutmeg. Chef Shack is selling its three food trucks, as well as its Seward neighborhood restaurant — which functions as a commissary kitchen for those bright red vehicles and for Chef Shack's farmers market appearances.

"We started talking about this nine months ago and both Lisa and I came to the conclusion that something had to give," Summer said by phone from Miami. "When we're doing a lot of things, it's a challenge, and we wanted to get some of our time back."

This doesn't spell the end for the business. Until a sale takes place, Chef Shack Ranch is still hosting private and special events (3025 E. Franklin Av., Mpls., 888-844-0017, chefshackranch.com). "Top Chef" contestant Justin Sutherland just cooked there for a smoked meat dinner.

The Minneapolis restaurant, which they operated since 2013, ended regular service in September. "We started to do more private events that scaled to a popularity that overshadowed being open to the public," Summer said.

The pair still own Chef Shack Bay City, a seasonal, weekend-only restaurant in Wisconsin. (6379 Main St., Bay City, Wis, 715-594-3060, chefshackbaycity.com)

"Our plan all along was at some point to focus fully on that Wisconsin location, and the time has come a bit sooner than we thought," Summer said. "It needs 100 percent of our attention."

That restaurant is currently undergoing a remodel and is expected to reopen by the end of March or the middle of April for Friday and Saturday dinner and Sunday brunch.

Don't look at it as a retirement, Summer said. Carlson, who does the savory cooking, and Summer, who does pastry, are still very involved in supporting restaurant entrepreneurs, especially women. "We're switching gears, but we are busier than ever," Summer said. "Just a different busy."

In other words, it was time to move on. "We've made our mark on the city," Summer said. "I think that's a nice lasting legacy — our food truck days in Minneapolis."

They're already talking to some potential (separate) buyers for the trucks, which come "fully loaded," Summer said. And the Seward restaurant is "a fantastic property for the next superstar."

Word's still out on whether the Bay City restaurant will fill the doughnut void.

"We've never really done the doughnuts there," Summer said. "But I definitely will consider it when we reopen, because I know that's gonna be a thing."