In a large bowl or stand mixer, mix flour, sugar, and salt. Dissolve yeast in warm milk and let it sit until foamy — about 5 to 10 minutes. Add the milk-yeast mixture and melted butter to the dry ingredients and knead until smooth, about 3–5 minutes. Shape it into a rectangle, wrap in plastic wrap, and refrigerate for 1 hour.
Place cold butter between two sheets of parchment paper. Use a rolling pin to shape it into a 6-inch square. If it’s too soft, chill it for a few minutes.
Roll the chilled dough into a 12-inch square. Place the butter block diagonally in the center, like a diamond. Fold the corners of the dough over the butter to enclose it completely, like wrapping a gift.
Roll the dough into a long rectangle, about 8×20 inches. Fold it into thirds, like a letter. This is your first “turn.” Wrap it and chill for 30 minutes.
Repeat the rolling, folding, and chilling process two more times for a total of three turns.
Each turn builds more layers — and more layers means flakier croissants. Don’t rush this step. Cold dough and butter make all the difference.
After the final rest, roll the dough out into a large rectangle, about 1/4-inch thick.
Use a sharp knife or pizza cutter to trim the edges and cut triangles roughly 5 inches wide at the base.
Starting at the wide end, gently stretch and roll each triangle toward the tip to form that classic crescent shape.
Cover the shaped croissants loosely and let them rise at room temperature for 1.5 to 2 hours.
Preheat your oven to 400°F (200°C). Mix the egg with milk and gently brush over each croissant — this gives them that glossy, golden finish.
Bake for 18–22 minutes until puffed and deep golden brown. Rotate the pan halfway through for even browning.
Let them cool on a wire rack for at least 10 minutes.
