Instructions
Dissolve yeast in warm milk with sugar. Let bloom for 10 minutes.
Mix flour and salt. Add yeast mixture and knead until smooth.
Cover dough and refrigerate for 1 hour.
Flatten butter into a square between parchment paper.
Roll dough, enclose butter, and laminate with 3 folds, chilling between each.
Roll dough into a rectangle, cut into triangles, and roll into croissants.
Proof until puffy and doubled in size.
Brush with egg wash and bake at 375°F (190°C) for 18–22 minutes until golden.
Notes
Keep dough and butter cold for best flakiness.
Do not rush the folding process.