How to Make Pain au Chocolat, Step by Step
If you're ready to make your own all-butter croissant dough at home, we have good news: You're also on the way to the best pain au chocolat you can imagine. The only other thing you need? Top-notch chocolate. Go for high-quality chocolate "batons" (such as Cacao Barry Extruded Bâtons Boulangers) for these pastries. Unlike bars or chips, chocolate batons are designed to distribute chocolate evenly and melt perfectly.
Step 1: Roll Out Croissant Dough and Cut into Rectangles
Line 2 baking sheets with parchment paper; set aside. Uncover refrigerated croissant dough, and transfer to a lightly floured surface. Lightly flour top of dough; roll into a 19- x 11-inch rectangle. Using a pizza cutter, trim edges to form an 18- x 10-inch rectangle; discard scraps. Cut dough into 12 (5- x 3-inch) rectangles. Place rectangles in a single layer on 1 prepared pan; cover tightly with plastic wrap, and refrigerate 15 minutes.
Step 2: Place Chocolate Batons on Dough
Place 1 dough rectangle on a clean work surface with a short side closest to you. Place 1 chocolate baking stick crosswise, 1/2 inch from bottom short side of dough rectangle. Place a second chocolate baking stick crosswise, 1 1/2 inches from top short side.
Step 3: Roll Dough Up, Proof, and Brush with Egg Wash
Starting at bottom short side, roll dough over first chocolate baking stick, and continue rolling over second chocolate baking stick and to top edge of dough. Firmly press seam to secure (chocolate baking sticks should be side by side, like binoculars, with a layer of dough in between). Place rolled dough, seam side down, on prepared baking sheet. Repeat with remaining dough rectangles and chocolate baking sticks, placing pastries at least 2 inches apart on both baking sheets. Proceed with recipe, or cover with plastic wrap and refrigerate up to 8 hours or overnight for deeper flavor.
Whisk together egg and milk in a small bowl (see recipe for exact amounts). Brush pastries lightly with egg mixture, using a paper towel to wipe away excess. Reserve remaining egg mixture in refrigerator. To proof pastries, add 2 cups hot water to a small bowl, and place in a cold oven. Place baking sheets with pastries, uncovered, in oven with hot water. Close door, and proof until pastries double in size and jiggle when you shake the baking sheets, 1 to 2 hours. Remove pastries and water from oven, and let pastries stand at room temperature 30 minutes. Meanwhile, preheat oven to 425°F. Place oven rack in middle position.
Step 4: Brush Again with Egg Wash, and Bake
Gently brush 1 baking sheet of pastries with a second coat of egg mixture. Place baking sheet on middle rack in preheated oven, and immediately decrease temperature to 375°F. Bake until golden brown and crisp, 18 to 24 minutes. Transfer pain au chocolat to a wire rack. Return oven temperature to 425°F. Repeat process with egg mixture and remaining pastries. Serve warm, or let cool completely, about 1 hour. (Pain au chocolat are best eaten the day they are baked.)