1-First assembled, prepare your equipment and review the full recipe, including any visual guides to get a clear picture. Then, cut the unsalted butter into pieces and combine it with 4 cups of all-purpose flour, 1/4 cup of granulated sugar, 2 teaspoons of salt, and 1 tablespoon of active dry or instant yeast in a mixing bowl. Slowly add 1 and 1/2 cups of cold whole milk while mixing to form the dough.

2-Next, knead the dough for 5 minutes until it is soft and passes the windowpane test, which means it stretches without tearing. Shape the dough into a ball, flatten it onto a lightly floured or silicone-lined baking sheet, cover it, and refrigerate for 30 minutes to let it rest. After that, roll the dough into a 14 by 10-inch rectangle on a silicone mat, cover it, and refrigerate for 4 hours or overnight to develop the flavors.

3-Creating the Butter Layer: For the butter layer, beat 1 and 1/2 cups of unsalted butter with 2 tablespoons of all-purpose flour until smooth; spread it into a 7 by 10-inch rectangle and chill for 30 minutes. This step is crucial for best baking techniques that add to the flakiness. Place the chilled butter on the rolled dough, fold the dough over to encase the butter, then roll it out on a floured surface into a 10 by 20-inch rectangle and fold it into thirds for the first turn.

4-If the dough feels warm, chill it for 30 minutes before continuing. Repeat the rolling and folding process two more times, with a 30-minute chill after the second fold to keep everything layered properly. After the third fold, cover the dough and refrigerate for 4 hours or overnight to let it rest fully.

5-Shaping and Baking: Once rested, roll out the dough into an 8 by 20-inch rectangle, then slice it vertically and horizontally into 16 triangles. Stretch each triangle to about 8 inches long, cut a small slit at the wide end, and roll it tightly from the wide end to the tip to form crescent shapes. Place the shaped croissants on lined baking sheets, loosely cover them, and let them rest at room temperature for 1 hour, then chill in the refrigerator for 1 hour.

6-Preheat the oven to 400°F and brush the croissants lightly with the egg wash made from 1 large egg and 2 tablespoons whole milk. Bake for about 20 minutes, rotating the pans halfway through; if they brown too quickly, lower the temperature to 375°F. Finally, cool the croissants on a wire rack before serving to enjoy their full flavor. This croissant recipe takes about 13 hours and 10 minutes total, with only 45 minutes of active time, making it manageable for any schedule.