Make the dough: In a mixing bowl combine the Bread Flour with Granulated Sugar and a pinch of Fine Salt on one side of the bowl and the Instant Yeast on the other (keep yeast away from direct contact with salt).
Add warmed Whole Milk and a little Water to bring the mixture together, then incorporate a small amount of softened Unsalted Butter. Mix until you have a smooth, slightly tacky dough, then knead briefly until elastic.
Bulk rest: Cover the dough and refrigerate for at least 1 hour to relax the gluten and firm up the dough for laminating.
Prepare the butter block: Place the Unsalted European-Style Butter between two sheets of parchment and beat/roll it into an even rectangle about two-thirds the size of your rolled dough. Chill until firm but pliable.
Laminate: Roll the chilled dough into a rectangle large enough to enclose the butter block. Place the butter on two-thirds of the dough, fold the uncovered third over the butter, then fold the remaining butter-covered third over (envelope fold) to encase the butter.
Perform folds: Roll the dough out into a long rectangle and do a letter fold (single or double fold as you prefer). Chill 20–30 minutes between folds to keep the butter firm. Repeat for a total of 3 turns (folds), chilling between each turn; after the final turn chill for at least 1 hour or overnight.
Shape: On a lightly floured surface roll the laminated dough into a thin rectangle, about 1/4 inch thick. Trim edges, cut the dough into long triangles, gently stretch each triangle, then roll from the base toward the tip to form croissants. Curve ends slightly for a crescent shape.
Proof: Place shaped croissants on a baking sheet lined with parchment, cover loosely, and let them proof at a warm spot until puffy and nearly doubled (this can take 1–2 hours depending on temperature).
Egg wash and bake: Whisk the Egg with a splash of Milk to make an egg wash and gently brush the croissants. Bake in a preheated oven at about 200°C (400°F) until deeply golden and crisp on the outside, about 15–25 minutes depending on size.
Finish: Transfer to a rack to cool slightly before serving. Keep croissants loosely covered for an hour if you like them softer, or enjoy them crisp and fresh straight from the oven.
