In a small bowl, add the warm water and yeast, and stir to dissolve the yeast. Sprinkle in ¼ teaspoon sugar and let sit until foamy, 5 to 10 minutes. If your yeast is alive, the mixture will bubble up.
In a large bowl, whisk together the flour, salt, and the remaining 2 tablespoons sugar.
Cut 10 tablespoons (141g) butter into ½-inch pieces and add it to the flour mixture. Set the remaining 6 tablespoons (85g) aside at room temperature to soften.
Add the milk, egg, and the proofed yeast into the well. Use a rubber spatula to stir it until a shaggy dough forms. Use your hand to bring the dough together into one mass.The dough will be soft and sticky, with bits of butter visible throughout. Resist the urge to add more flour or continue kneading.
Lightly oil a large bowl—you can use the same bowl used to mix the dough. Transfer the dough into it and cover with plastic wrap. Let it rise in the fridge for at least 1 hour or up to 18 hours.
Lightly sprinkle flour on a clean work surface and turn the chilled dough onto it. Lightly flour the top of the dough. Use a rolling pin to roll it into a 15x10-inch rectangle, about 1/4 inch thick, with the long side closest to you.Use your fingers or offset spatula to spread about 1 1/2 tablespoons softened butter on the rolled dough into a very thin, even layer. Sprinkle a few pinches of flour over the butter. Pick up and fold the left third of the dough over the middle third and the right third over that. You’ll have a narrow rectangle with the long side perpendicular to you. This is called a trifold. Transfer the dough onto the prepared sheet pan, cover loosely with plastic wrap, and chill in the freezer for 5 to 10 minutes, until the butter firms up. Repeat this process three more times for a total of four trifolds—start by rolling it into a rectangle and end with chilling it in the freezer. After the last trifold, chill the dough for about 15 minutes in the freezer. The dough should be firm, but pliable enough to roll out.
Line 2 sheet pans with parchment paper and set them aside.
Place the chilled dough on your work surface with the long side closest to you. Use a sharp knife to cut it in half crosswise—you’ll have 2 pieces about 5x5-inches each. Keep a piece in the fridge, while you shape the other.
Lightly sprinkle flour on your work surface. Roll the dough into a 12x6-inch rectangle, about 1/4 inch thick, with the long side closest to you. Use a sharp chef’s knife to cut it crosswise into 6 2x6-inch rectangles. Cut each rectangle in half on the diagonal to create 2 triangles. You will end with 12 triangles.
Place 1 triangle on your work surface with the point away from you. Cut a shallow 1/4-inch slit in the center of the base of the triangle. Gently tug each side of the base apart—while optional, this helps elongate and shape the crescent roll.Roll the base of the triangle away from you and towards the point, ending with the point tucked under. Curve the ends to curve the roll slightly into the shape of a crescent. Transfer it onto a prepared sheet pan, which will hold 12 rolls. Shape the remaining rolls and spread them out evenly on the sheet pan.Cover them loosely with plastic wrap and set aside at room temperature. In the meantime, cut and shape the remaining dough chilling in the fridge.
Let the rolls rise at room temperature for 1 hour to 1 hour 15 minutes, until almost doubled in size. Gently poke one. If it slowly springs back, but holds an ident, it’s ready to be baked.
Set the oven racks to the top and bottom thirds.
Use a pastry brush to lightly brush the tops of each roll with whole milk.
Bake the rolls until puffed and golden brown, 13 to 15 minutes, rotating the sheet pans from front to back and from top to bottom, halfway through.
Place the sheet pans on wire racks. While the rolls are still hot, brush them with melted butter, if you’d like. Serve them warm—they’ll be flaky and oh so tender. Store leftovers in a resealable bag or airtight container at room temperature for up to 3 days. To reheat, place the rolls on a sheet pan and reheat them in a 325°F oven until warmed through, about 5 minutes.