1. Gather all essential ingredients for the dough, filling, and glaze to ensure a smooth baking process.

2. For the dough, mix all-purpose flour, unsweetened cocoa powder, instant dry yeast, and salt in a large mixing bowl.

3. Separately, combine warm whole milk, granulated sugar, unsalted butter, and a beaten egg. Optionally, add an extra egg yolk and use European Style Salted Butter for a brioche-like dough.

4. Gradually mix the wet ingredients into the dry mixture, kneading until a smooth, elastic dough forms. Leave the dough to rest and rise until it doubles in size.

5. Roll the dough into a large rectangle, about 12 x 18 inches, ensuring an even thickness throughout.

6. Prepare the filling by combining light brown sugar, black cocoa or Dutch-process cocoa powder, and ground cinnamon.

7. Spread the filling mixture evenly over the rolled-out dough and sprinkle chopped baking chocolate or chocolate chips for added flavor.

8. Roll the dough tightly lengthwise into a log shape, ensuring a compact roll.

9. Cut the rolled dough into equal pieces using unflavored dental floss or a serrated knife for clean cuts.

10. Grease your baking pan and place the rolls into it, spacing them slightly apart.

11. Cover the baking pan and allow the rolls to rise again until doubled in size, approximately 25–30 minutes, depending on room temperature.

12. Preheat the oven to 350°F (177°C) in preparation for baking the rolls.

13. Bake the rolls for 25–28 minutes, covering them loosely with aluminum foil halfway through to prevent over-browning.

14. Once baked, allow the rolls to cool slightly for about 10–20 minutes before adding the glaze.

15. For the glaze, melt unsalted butter and combine it with milk or dark chocolate chips, whole milk, powdered sugar, and vanilla extract. Mix until smooth.

16. Pour the melted chocolate glaze generously over the warm rolls, ensuring a glossy and luxurious finish.

17. Optionally, use other glaze variations, such as an espresso glaze, to personalize the flavor.

18. Serve the chocolate cinnamon rolls warm for the best experience and enjoy their gooey, decadent texture.

19. Any leftovers can be stored in an airtight container to maintain freshness, refrigerated for up to a week, or frozen for long-term storage.

20. Reheat rolls when ready to eat, and optionally add fresh glaze to enhance their texture and flavor before serving.