Pastry chef Christina Tosi's big hit bakery Milk Bar looks to be doing some more expansion, and it's arriving in the Bay Area in two ways, including a pop-up at San Francisco's Ferry Building.

Milk Bar, which began life as Momofuku Milk Bar and was around the corner from David Chang's famed Momofuku Noodle Bar in New York's East Village, has been expanding steadily over the last decade, and now delivers nationwide via its online store. There are now multiple Milk Bar locations in New York, as well as outposts in Washington, D.C., Las Vegas, Toronto, Boston, and Los Angeles.

Thus far, the Bay Area had been left out of the fun, but as the Chronicle reported last month, Milk Bar is now doing deliveries out of a DoorDash kitchen in Redwood City. Sadly, the delivery range for that operation does not include San Francisco — just the Peninsula. But fans can go directly there for Tosi's famed Milk Bar Pie (formerly known as "Crack Pie"), and birthday cake truffles. It's located at 1531 Main Street in Redwood City, and it's a ghost kitchen where you can also get food from RT Rotisserie, and The Halal Guys.

Then, on July 31 and August 1, Milk Bar is popping up at Gott's Roadside at the Ferry Building as part of its Birthday Do-Over Month promotional tour, which is also making stops in Chicago and Seattle.

Guests who reserve spots will get the opportunity to purchase cookies, Milk Bar Pie, B'Day Truffles, as well as "a limited time special dessert offering from Milk Bar & Gott's." There are also some more surprises promised.

"Giveaways, surprises and more — consider this your invite to get loud, be ridiculous, and get down with some treats," the website says.

The Chronicle surmised that all this sudden activity is a sign that a brick-and-mortar location for Milk Bar in the Bay Area may be in the cards — and maybe even more than one, hence the Peninsula market test. Milk Bar is reportedly doing similar things in Atlanta, Houston, Dallas, and Minneapolis.