Tatum Sinclair’s first job out of culinary school was as a line cook under Stephen Gillanders at the now-shuttered Intro. She worked hard and fast and kept to herself. “What do you do outside of work?” Gillanders finally asked her one day. “I go to bakeries,” Sinclair answered. How many had she been to? “Eighty-six.” There was a spreadsheet on her phone.

The next day, Gillanders moved her to the pastry station, and Sinclair’s obsession became her life’s work. After a two-year stint in New York City, she returned to Chicago in 2017 to help Gillanders open S.K.Y. on a shoestring budget. “I wasn’t trying to make the best desserts but make them just simple and delicious,” she recalls. Her banana budino and other sweet and savory goods helped the restaurant become a hit, and she joined Gillanders as he opened more spots. From her black truffle puff bread at Apolonia to her Whole Lemon (a Pavlova that uses all parts of the fruit) at Valhalla, her creations stood out.

Sinclair, 29, will soon have a stage to herself. Haven, which will likely launch this spring in West Town, will be backed by Gillanders but is Sinclair’s baby. During the day she’ll serve coffee and carryout pastries; at night the place will transform into a dessert-tasting counter. The early seating will have a six-course menu (pricing TBD, but possibly $68), and the later one will allow guests to indulge in as many as 12 (possibly $120). “It’s a small space, and ideally we’d like to do it like an omakase, but I’m still trying to figure it out,” Sinclair says. Expect to see variations of her signature sweets, such as seasonal Pavlovas, but don’t count out humbler creations. As we talk at Valhalla, she pulls a batch of chocolate chip cookies from the oven and sprinkles them with flaky sea salt. She passes a couple — crisp but melting and barely able to contain their butter — across the counter, a gesture she will no doubt repeat many times once Haven opens.