Whisk the warm milk, yeast, and sugar together in a stand mixer bowl. Cover and let sit for about 5 minutes until foamy.

Add salt, butter, and 2 cups (250g) of flour. Beat on medium speed for 2 minutes. Add the remaining flour and beat until a soft dough forms.

Knead the dough in the mixer for an additional 5 minutes or by hand until slightly tacky.

Lightly grease a large bowl and place the dough inside, covering it. Allow to rise for 1.5–2 hours or until nearly double in size.

Flatten the dough into a 10×14-inch rectangle on a floured surface and refrigerate for 20 minutes.

For the first lamination, line butter down the center of the dough, fold the edges over to enclose the butter, and roll out to a 9×12-inch rectangle. Refrigerate again for 20 minutes.

For the second lamination, repeat rolling and folding, then refrigerate for 20 minutes.

For the third lamination, repeat rolling and folding one last time, then refrigerate for 20 minutes.

Roll out the final time to a 9×12-inch rectangle, roll it up into a log and cut into 5 rolls.

Grease a 9×5-inch loaf pan and place rolls seam side down. Cover and let rise for 45–60 minutes until slightly puffy.

Preheat the oven to 350°F (177°C).

Whisk the egg and water together. Brush the risen rolls with the egg wash. Bake for 1 hour until golden brown, tenting with aluminum foil after 25 minutes.

Cool in the pan for 30 minutes, then on a wire rack for an additional 15 minutes before slicing.