2/3 cup warm milk + 1/2 cup warm water (110 degrees F)
2 tablespoons granulated sugar
1 packet (2 1/4 teaspoons) active dry yeast
4 tablespoons unsalted butter, melted and cooled slightly
2 teaspoons kosher salt
3 cups unbleached all purpose flour, plus more if needed
1 large egg

Combine the warm milk, warm water, granulated sugar, and active dry yeast. Whisk to combine. Let sit 10 minutes.

Add the melted butter, salt, and flour and mix until a shaggy dough forms and pulls away from the sides of the bowl. Turn onto a lightly floured surface and knead by hand until smooth and elastic, about 8 minutes.

Transfer the dough to a lightly greased bowl, cover, and set aside in a warm place. Allow to rise until roughly doubled in size, about 1 to 1 1/2 hours.

Deflate the dough and transfer to a flat, lightly oiled surface. Gently flatten into a large circle, then pull in one edge at an angle 2/3 of the way. Press down with your knuckles. Pull in the other edge at an angle, overlapping the other edge, to create a tall triangle. Press down with your knuckles again. (See video for example.) Roll into a log starting at the thinnest point, being sure to press to seal edges after each turn.

Place, seam-side down in a lightly greased loaf pan. Cover with a damp kitchen towel and let sit until risen about 1” over the edge of the loaf pan.

Preheat the oven to 425°F. Lightly beat the egg with a teaspoon of water and a sprinkle of salt. Brush the top of the loaf with the egg wash.

Decrease heat to 350°F and bake until golden brown and cooked through, about 35-40 minutes.