- 3½ cups all-purpose flour, divided, plus more for dusting
- ⅔ cup water, heated to 115º
- 3 teaspoons active dry yeast, divided
- ⅔ cup room-temperature whole milk
- ¼ cup granulated sugar
- 1½ tablespoons kosher salt
- 2½ sticks unsalted butter, chilled, plus 3 tablespoons, softened
- 1 egg, beaten
1. Make the preferment: In a medium bowl, whisk together 1 cup of the flour with the water and a pinch of the yeast until smooth. Cover in plastic wrap and let sit somewhere warm for 5 hours.
2. In the bowl of a stand mixer fitted with the dough hook attachment, combine the preferment and the remaining 2½ cups of flour, the remaining yeast, the milk, sugar, salt and softened butter. Mix until a dough comes together, then transfer to a lightly floured work surface and knead until smooth, 2 minutes. On a parchment-lined sheet pan, shape the dough into a rectangle and wrap in plastic wrap. Refrigerate overnight.
3. The next day, laminate the dough: On a lightly floured work surface, roll the dough into a 14-by-20-inch horizontal rectangle.
4. On a floured sheet of parchment paper, beat the 2½ sticks of unsalted butter with a rolling pin to flatten. Using flour as needed, roll the butter into a 9-by-13-inch rectangle. Peel off the parchment paper and place the butter insert on the right half of the dough.
5. Fold the dough over the butter and seal the edges. Fold the top third and bottom third of the dough in like a letter and place the folded dough, seal down, on a parchment-lined sheet pan. Chill for 30 minutes.
6. Roll the chilled dough into a 14-by-16-inch horizontal rectangle, then complete a trifold, folding the left and right ends in like a letter. Chill the dough for 30 minutes. Repeat this process 2 more times for a total of 4 trifolds, and then chill again for 30 minutes.
7. Roll the laminated dough into a 9-by-40-inch horizontal rectangle (this will take about 10 minutes). Using a sharp knife, cut 5-inch notches into the top edge of the rectangle. Begin to cut triangles, cutting to the centerpoint of each notch. You should end up with 14 triangles.
8. Working from the wide end of the triangle, roll the dough into a croissant shape, tucking the end of the dough underneath. Place the rolled croissants on 2 parchment-lined sheet pans, 2 inches apart. Lightly brush each one with some of the beaten egg, then place them somewhere warm to proof for 2 hours, until the croissants have risen and you can see the layers of butter.
9. Preheat the oven to 350º. After proofing, brush the croissants again with the remaining egg, then bake, rotating every 10 minutes, until golden brown and risen, 30 minutes. Let cool completely, then serve.