01 - In a large bowl, combine flour, sugar, salt, and yeast, placing yeast away from direct salt contact. Add lukewarm milk, melted butter, and egg. Mix thoroughly until a sticky, uniform dough forms.
02 - Knead the dough for 7–10 minutes until smooth and elastic. Transfer to a greased bowl, cover, and let rise for 1 hour until doubled in volume.
03 - Punch down the dough and shape into a rectangle. Cover and refrigerate for 30 minutes to relax the gluten.
04 - On a lightly floured surface, roll the dough into a 12 x 16-inch rectangle. Arrange cold butter slices over two-thirds of the dough surface.
05 - Fold the unbuttered third over the butter, then fold the remaining third on top to create a neat rectangle. Rotate 90° so the open edges face you.
06 - Roll into a 12 x 16-inch rectangle again. Perform a letter fold into thirds, wrap tightly, and refrigerate for 30 minutes.
07 - Repeat the rolling, folding, and chilling process two additional times, for a total of three complete turns to develop proper layers.
08 - After the final chill, roll dough to approximately 8 x 16 inches. Roll tightly from the short edge into a compact loaf shape.
09 - Place seam-side down in a greased 9 x 5-inch loaf pan. Cover loosely and let rise until doubled, about 1 hour.
10 - Preheat oven to 375°F. Whisk egg and 1 tablespoon milk for egg wash. Brush the entire loaf surface evenly.
11 - Bake for 35–40 minutes until deeply golden and the loaf sounds hollow when tapped. Tent with foil if browning too rapidly.
12 - Let cool in the pan for 10 minutes, then transfer to a wire rack. Cool fully before slicing to maintain structure.