Layer upon layer of butter and dough produce the ultimate French breakfast treat. This pastry classic dates back to 1686, when Austrian bakers created this treat to commemorate a military victory over Turkey.

To prepare the dough block: Pour the warm milk into a small bowl and whisk in 1 teaspoon of the sugar. Whisk in the yeast and set aside for 10 minutes, or until the yeast is activated and the mixture is bubbling.

In the bowl of a stand mixer fitted with a paddle attachment, combine the flour, remaining 2 tablespoons of sugar, the salt, and cold butter pieces. Blend on medium speed until the butter is cut into tiny pieces and the mixture resembles bread crumbs. Add the yeast mixture and the cold milk. Switch to a dough hook and mix on lowest speed for 1 ½ to 2 minutes, until the liquid is absorbed and has formed a very rough mass. Dust a work surface lightly with flour and turn the dough out onto it. Knead the dough 3 to 5 times, just to finish bringing it together. The dough will not be smooth or elastic; it will become fully kneaded and smooth during the rolling and turning process ahead. Don’t overwork the dough now or you’ll have trouble rolling it later. Wrap the dough loosely in plastic wrap (to allow a little room for expansion) and refrigerate for 30 to 60 minutes.

To prepare butter block: Cut the butter into ½-inch pieces, toss with the flour, and refrigerate for 20 minutes. In the cleaned stand mixer fitted with the paddle attachment, beat the floured butter on medium speed, scraping down the bowl once or twice with a bowl scraper, for 1 to 2 minutes, until the butter and flour form a smooth mass. You are not trying to beat air into the mixture, just make it pliable and smooth while keeping it cold. Scrape the butter onto a piece of parchment paper or plastic wrap, wrap it up, and refrigerate while you roll out the dough.

To incorporate the butter into the dough: Dust the work surface with flour. Set the dough in the center and dust the top with flour. Roll the dough into a 15 by 12-inch rectangle with a short side parallel to the edge of your work surface. Gently pull or stretch the dough to form straight edges and sharp corners. Brush any flour from the surface. Visually divide the dough crosswise into 3 equal, 5-inch wide sections (you can lightly mark the dough with a ruler or the back of a knife if you wish). Spread the cold but pliable butter evenly over the top two sections of dough, leaving the bottom third empty and leaving a ½-inch border around the edges of the buttered sections. This is best done with your fingers, since the butter isn’t quite warm enough to spread easily with a spatula. Alternatively, you can place the butter between two sheets of plastic and roll it into a 9 ½ by 11-inch rectangle. Peel off one sheet of plastic, invert the buttered rectangle over the dough rectangle, center it, and peel off the other sheet of plastic.

To encase the butter with a letter fold (First turn): Fold the empty bottom third up over the center third of the dough. Then fold the top third down over the center. Pinch together the seams along the bottom and sides of the dough. Roll your rolling pin across the top briefly and gently 3 or 4 times to help seal the seams. This completes both the incorporation of the butter and your first turn of the dough. If the butter has become warm and squishy, wrap the dough in plastic and refrigerate for 1 hour before continuing with the second turn. If you have worked quickly and the butter is still cold yet pliable, continue with the next turn.

Book fold (Second turn): Position the dough with the short side parallel to your work surface and the long fold on your left. Dust the dough with flour and roll it into a 20 by 12-inch rectangle. Brush any flour from the surface of the dough. Fold the dough using the book fold method: Fold the two short