In a bowl, combine warm milk, sugar, and yeast. Let it sit for about 5-10 minutes until frothy.

In a larger bowl, mix the flour and salt, then gradually add the yeast mixture. Stir until a dough forms.

Transfer the dough to a floured surface and knead for about 5-7 minutes until smooth.

Place it in an oiled bowl, cover it with a damp towel, and let it rise in a warm place for about 1 hour or until doubled in size.

While the dough is rising, take two sticks of cold unsalted butter and pound them between two sheets of parchment paper until flat and about 1/2 inch thick.

Chill it again until firm.

Roll out the risen dough into a large rectangle.

Place the butter slab in the center and fold the dough over to encase it.

Roll out the dough again into a rectangle, then fold it into thirds (like a letter).

Repeat this process two more times with rests in between to develop those flaky layers.

After the final fold, roll out the dough into a large rectangle, then cut it into triangles.

Starting from the wide end, roll each triangle tightly towards the point to shape the croissants.

Place them on a baking sheet lined with parchment paper, let them rise for another hour until puffy.

Preheat your oven to 400°F (200°C).

Brush the risen croissants with a whisked egg and bake for 15-20 minutes, or until golden brown.

Allow them to cool slightly before devouring these freshly baked delights.