Make the Chocolate Sheet

• In a medium microwave-safe bowl, whisk together the cake flour, cocoa powder, sugar, and milk until smooth. Microwave for 30 seconds, then stir.
• Add the finely chopped chocolate and stir until mostly melted.
• Separate the egg whites from the yolk. Measure 20 g egg white and add it to the bowl. Whisk the remaining egg and set it aside for later.
• Microwave the mixture for 1 minute total, heating in 20-second intervals, stirring well each time.
• Add the butter and mix until fully incorporated. Microwave for another 20-30 seconds, just until the surface edges look slightly dry. Using a spatula, knead the mixture lightly— it should form a thick paste.
• Spread the chocolate paste onto plastic wrap and shape it into a 15 × 12 cm rectangle. Wrap tightly, place on a metal tray, and refrigerate until firm.

Make the Bread Dough

Prep

• Measure 10 g egg from the reserved egg and set aside for the egg wash.
• Use the remaining egg and combine with milk to make 65 g total egg + milk.

Stand Mixer Method

• Add the flour, yeast, sugar, salt, water, and egg–milk mixture to the bowl of a stand mixer. Mix on low speed until a shaggy dough forms. Increase to medium speed and knead for 6–8 minutes, until the dough becomes smooth and elastic.
• Add the butter and continue kneading until fully incorporated and the dough passes the windowpane test.
• Shape into a ball, place in a lightly greased bowl, cover, and let rise at 30°C for 60 minutes or until doubled in size. 

Hand Kneading Method

• In a large bowl, mix the flour, yeast, sugar, salt, water, and egg–milk mixture until a rough dough forms. Transfer to a clean work surface and knead for 10–12 minutes, until smooth and elastic.
• Knead in the butter gradually until fully absorbed.
• Shape into a ball, place in a lightly greased bowl, cover, and let rise at 30°C for 60 minutes or until doubled in size. 

Shape the Dough

• Once doubled, remove the dough from the bowl. If sticky, lightly dust with flour.
• Roll the dough into a 28 × 17 cm rectangle. Place the chilled chocolate sheet in the center. Fold the left and right sides over the chocolate sheet, pinching to seal. Pinch the top and bottom edges to fully enclose the chocolate.
• Using a rolling pin, press down on the dough firmly, starting from the middle upward and then downward (or left and right) to evenly distribute the chocolate. Do not roll straight through immediately—this prevents uneven spreading. Roll out to 36 × 20 cm. Fold the dough into thirds.
• Rotate 90 degrees and roll again to 36 × 20 cm. Fold the dough into thirds.
• Rotate another 90 degrees and roll to 29 × 17 cm. 
• Trim about 1 cm from the edges to straighten. Cut into 6 equal strips, about 4.5 cm wide each.
• Slice each strip lengthwise down the center, leaving 2 cm intact at both the top and bottom. Loop the top edge over the center opening and the bottom edge under it, making sure they loop in opposite directions for a clean twist. 
• Take the two end pieces and twist them together for a extra mini twist bread. 
• Place on a lined baking sheet, leaving space between each piece.

Proof & Bake

• Cover and proof at 30°C for 60 minutes, or until about 1.5× in size.
• Preheat the oven to 392°F (200°C).
• Whisk together the reserved 10 g egg and 5 ml milk. Let the dough surface dry slightly, then lightly brush with egg wash.
• Bake for 12–14 minutes, or until golden brown on both sides.