Marshmallows, marshmallows, and more marshmallows.

"We serve items that are all completely marshmallow based: From individual marshmallows, to s'mores, to smacos — which are our s'mores tacos — to even or marshmallo- topped drinks," said Lindzi Shanks, co-owner of XO Marshmallow. "My joking unofficial title is the s'mores sommelier." 

Shanks just is one half of the team that started the gourmet marshmallow café. Kat Connor is the other.

"My unofficial title is the marshmallowist," Conner said.

Officially, Connor is an attorney, but after making marshmallows at her graduation party, her career took a different turn.

"That's when I was told 'you have to sell these' by everybody," Conner said.

She partnered with Shanks and began selling marshmallows online, then raised money through Kickstarter to open a store.

"First time we walked to the space, the space itself was horrible," Shanks said.

They transformed an old salon, into a whimsical marhsmallow wonderland.

"It's this idea it's this nostalgic feeling," Shanks says. "People get to come in and have a café completely dedicated to a memory, if you will."

As nice as the restaurant is, the kitchen is where the real marshmallow magic happens.

Pastry chef Melissa Humphrey makes sure the sugar, corn syrup and water, is the perfect temperature before combining it with a mix of water and gelatin.

"If you're 5 degrees under or 5 degrees over the marshmallow won't turn out," Humphrey said.

The marshmallow mix goes from the bowl, to the pan, and into the store for people to enjoy. And they are definitely enjoying.

"It's cool," said customer Sarajane Fein. "I mean, I don't think I've ever tried a flavored marshmallow before."

And that's what makes this new twist on an old favorite, so sweet.

"People are like always very, very happy, "Connor said. "And that makes us really happy too."

For those who love marshmallows and can't make it to the store in Chicago, XO Marshmallows are available to order online.