Starbucks Inspired Butter Croissants

Method

1. 1Day 1: Mix bread flour, sugar, yeast, and salt in a stand-mixer bowl. Add cold milk and softened butter; mix on low for 3 minutes, then medium-low for 4 to 5 minutes until cohesive and moderately smooth but not fully elastic.
2. 2Shape the dough into a 7-inch square, wrap tightly, and refrigerate for 30 minutes, then freeze for 20 minutes. The dough should be cold and firm but still bend without cracking.
3. 3Arrange the cold European-style butter between parchment sheets and pound, then roll, into an even 7-inch square about 3/8 inch thick. Chill until flexible like modeling clay—neither greasy nor brittle.
4. 4Roll the dough to a 7-by-14-inch rectangle. Place the butter square on one half, fold the other half over it, and pinch all edges closed so no butter is exposed.
5. 5With the seam to one side, tap the packet with the rolling pin to lengthen it, then roll to roughly 8 by 24 inches. Brush away excess flour, fold the top third down and bottom third up like a letter, wrap, and chill 30 minutes.
6. 6Rotate the dough 90 degrees and repeat the 8-by-24-inch roll and letter fold twice more, chilling 30 to 45 minutes after each fold. If butter softens or smears, stop and chill; if it fractures, wait 5 minutes before rolling.
7. 7After the third fold, wrap and refrigerate for at least 8 hours or overnight so the gluten relaxes and the layers become fully cold.
8. 8Day 2: Roll the dough on a lightly floured cold surface to a 10-by-42-inch rectangle about 1/8 inch thick, trimming uneven edges. Mark 5-inch intervals along one long edge and offset marks on the opposite edge to guide 12 long triangles.
9. 9Cut 12 triangles with a pizza wheel. Gently stretch each to about 10 inches, notch the center of the base by 1/2 inch, and roll from base to tip without crushing layers. Place tip-side down on two parchment-lined pans with room to expand.
10. 10Whisk the egg with 1 tablespoon milk and brush a very thin coat over the croissants, avoiding cut laminated edges. Proof at 74 to 78°F for 2 to 3 hours until visibly expanded, delicate, and jiggly when the pan is nudged; butter must not leak.
11. 11Heat the oven to 400°F (204°C) near the end of proofing. Brush the croissants lightly again, bake for 8 minutes, reduce to 375°F (191°C), rotate the pans, and bake 12 to 16 minutes more until deeply golden and 200 to 205°F inside.
12. 12Cool on the pans for 5 minutes, then transfer to a rack for at least 20 minutes. Cutting too soon compresses the steaming interior; a cooled croissant should show open, irregular honeycomb layers rather than a breadlike spiral.