In a large bowl, combine bread flour, sugar, and salt on one side. On the other side, sprinkle the yeast, keeping it separate from the salt. Pour in cold milk gradually and mix until the dough forms.

Knead the dough on a lightly floured surface for 8-10 minutes until smooth and elastic. Return it to the bowl, cover with plastic wrap, and chill in the refrigerator for 1 hour.

Place cold butter between two sheets of parchment paper and pound or roll into a 7x7 inch square. Chill in the fridge until firm but pliable.

Roll chilled dough out into a 21x10 inch rectangle. Center the butter block on one half, fold the other half over to cover, and seal the edges tightly.

Roll the dough lengthwise to about 20x10 inches, fold into thirds like a letter (first turn). Wrap in plastic and chill for 1 hour.

Repeat rolling and folding process two more times (second and third turns), chilling for 1 hour between each.

After the last turn and chill, roll dough into a 20x10 inch rectangle and cut into 12 equal triangles.

Roll each triangle tightly from base to tip to form classic crescent shapes.

Place shaped croissants on parchment-lined baking sheets and cover lightly. Proof in a warm, draft-free area until doubled in size, about 1.5 to 2 hours.

Preheat the oven to 375°F (190°C).

Whisk egg with cold water to make egg wash and gently brush over croissants.

Bake croissants for 18-20 minutes or until puffed and deeply golden.

Allow croissants to cool on a wire rack before serving.