Gather ingredients: flour, butter (for lamination), yeast, milk or water, sugar, salt, eggs (optional), and vanilla (optional)
Prepare butter block: shape butter into a flat rectangle, chill until firm but pliable
Make dough: mix flour, yeast, sugar, salt, and milk/water; knead until smooth and elastic
Add butter incorporation step: chill dough until firm
Laminate: roll dough into a rectangle, place butter block on top, fold dough over butter, seal edges
Roll and fold: roll into a long rectangle, fold into thirds (letter fold), chill
Repeat lamination: perform 2 more letter folds, chilling 20–30 minutes between each
Rest dough: after final fold, chill dough thoroughly (at least 1 hour)
Shape: roll dough to desired thickness, cut into triangles, make a small slit at the base of each triangle
Form croissants: roll triangles from base to tip, gently stretch to even thickness
Proof: place on baking sheet, cover, let rise until slightly puffy (typically 1–2 hours depending on temperature)
Preheat oven: bake at 200–220°C (390–425°F)
Egg wash: brush with beaten egg or milk/egg mixture
Bake: bake until deep golden brown (typically 15–25 minutes)
Cool: cool on a rack 10–20 minutes before serving