As a kid growing up in Queens, New York, Thiago Silva downed bowls of Apple Jacks and Cocoa Puffs for breakfast. Sometimes he’d grab a few donuts on his way to school, too. "I loved anything fun and sugary for breakfast," Silva says. "You know, basic fat kid problems!"

Now, Silva’s the executive pastry chef of Union Fare, a massive multipurpose food hall in Manhattan. He’s been working insane hours (even for a chef) to open the coffee bar, restaurant, bakery and food market spaces in rapid-fire succession over just a few weeks. That might explain his current food fixations. "I’m obsessed with breakfast since I don’t get to eat it anymore" he says. "I eat coffee for breakfast now."

Before this gig, Silva had gotten a lot of buzz for his crazy mashup donut concoctions, but when it came to launching completely new dessert and pastry menus, he decided that "everyone’s doing donuts right now." And since smashing childhood favorites together with professional panache is sorta his thing (think Apple Jacks PopTarts and S’Mores Pizza), he found his challenge in the swankest of breakfast pastries: the croissant.

Over the course of a few weeks, he figured out that if he nailed the right size, kind, and proportions of solid ingredients, he could fold them into the butter blocks that he works into the croissant dough itself. He found that they’d bake into colorful, flaky layers that he could fill and top with a variety of playful ingredients in distinctly American presentations.

It’s not something you want to stop eating after a few bites, and it’s not something pretty you come in just to Instagram.

His most popular flavor so far, the Birthday Cake Croissant (pictured above), has sprinkles folded into the butter. He fills it with a pastry cream lightened by whipped cream with more sprinkles thrown in, and then showers it with a "fairy dust" of ground sprinkle powder. "It’s super crispy, flavorful, and not too sweet. It’s not something you want to stop eating after a few bites, and it’s not something pretty you come in just to Instagram," Silva promises. The first day the bakery opened, he sold out of his initial twenty-five. Within a week, two hundred were gone by one o’clock. Now, he preps three hundred for his busiest days.

"Once I figured out that I could make a laminated dough with chunks of things in it and make it work, I didn’t want to stop," he laughs.

Now, there’s a red velvet with cocoa powder and red coloring in the butter block, filled with cream cheese buttercream and topped with red-velvet cake crumbs and red-velvet glaze. The matcha has just enough tea and powdered sugar so as to not become bitter. The "Everything" is unfilled and topped with salt, pepper, sesame seeds, and poppy seeds. Silva’s favorite, the crème brûlée, is a plain dough filled with cream cheese custard and topped with torched caramel.

If you’re gunning for a specific flavor, get in line early; Silva is still scaling up for growing demand, but the process isn’t rushed and each batch takes four days to make. "We’re making it hard on ourselves, in a way" he mourns. "But I want a really good croissant dough!"

Here's the step-by-step process for Silva's Cookies and Cream Croissants:

It all starts with a poolish starter of yeast, water, and flour that he lets sit overnight for fifteen hours. He makes knock-off Oreo cookies from scratch to fold into the butter blocks the next day, since regular Oreos were too sweet and the vegetable oil in the shortening melted into a gooey mess. That butter goes into the dough, which he rolls, folds, and rolls again like any other traditional croissant. It sits overnight so that the flavors deepen and the yeast gains some serious legs. The next day, it’s shaped and laminated. On the fourth day—finally—the batch is baked. 

Each filling is buttercream-based, then lightened with either custard or whipped cream. The Cookies and Cream filling has more crispy chocolate-cookie crumbs folded in, with each batch scooped into pastry bags that can fill about 40 croissants at a time.

He makes a long slice down each croissant, rather than piping them in through a small hole, so that there’s filling in every bite.

Then he drizzles it with vanilla icing and tops each with more cookie crumbs.