# What you need:
→ Sourdough Croissant Dough
01 - 3.5 cups bread flour
02 - 0.5 cup active sourdough starter at 100% hydration
03 - 0.75 cup whole milk, cold
04 - 0.25 cup granulated sugar
05 - 2 teaspoons fine sea salt
06 - 2 tablespoons unsalted butter, softened
07 - 1 large egg for egg wash
→ Butter Layer
08 - 2 cups unsalted European-style butter, cold for laminating
→ Filling
09 - 4.2 ounces high-quality dark chocolate at least 60% cocoa, cut into 12 batons
# How to make it:
01 - In a large bowl or stand mixer, combine flour, sourdough starter, cold milk, sugar, salt, and softened butter. Mix until a rough dough forms. Knead for 4 to 5 minutes until smooth and slightly elastic. Cover and let rest at room temperature for 30 minutes.
02 - Place dough in a lightly oiled bowl, cover with plastic wrap, and bulk ferment at room temperature for 2 to 3 hours, performing 2 stretch-and-folds at 1-hour intervals. Transfer to refrigerator and chill overnight for 8 to 12 hours.
03 - Place cold butter between two sheets of parchment paper. Pound and roll into an 8 by 8 inch square. Refrigerate until firm.
04 - On a lightly floured surface, roll dough into a 12 by 12 inch square. Position butter block in center, fold dough edges over to completely encase butter. Roll out to a 24 by 8 inch rectangle. Fold into thirds using a letter fold. Chill for 30 minutes. Repeat rolling and folding process twice more, chilling 30 minutes between each turn.
05 - Roll laminated dough out to a 24 by 12 inch rectangle, approximately 0.15 inch thick. Cut into 12 long triangles with a base of about 4 inches. Place one chocolate baton at the wide end of each triangle, then roll tightly toward the tip. Arrange on parchment-lined baking sheets with tip side down.
06 - Cover croissants loosely with plastic wrap and proof at room temperature for 4 to 5 hours, or until doubled in volume and very puffy. If kitchen temperature is cool, proof in a slightly warm, draft-free location.
07 - Preheat oven to 400 degrees Fahrenheit. Beat egg with 1 tablespoon water and gently brush croissants with egg wash. Bake for 18 to 22 minutes until deep golden brown and crisp exterior forms.
08 - Transfer croissants to a wire rack and allow to cool for at least 15 minutes before serving.
