Step 1: Make the Dough

1. In a small bowl, combine the warm milk, granulated sugar, and active dry yeast. Let sit for 5–10 minutes, or until the mixture is frothy. This indicates the yeast is activated.
2. In a large mixing bowl (or the bowl of a stand mixer), combine the melted butter and egg. Add the yeast mixture and mix until combined.
3. Gradually add the flour and salt, mixing until a soft dough forms. If using a stand mixer, knead with the dough hook for 5–7 minutes. If mixing by hand, knead on a floured surface for 8–10 minutes until the dough is smooth and elastic.
4. Transfer the dough to a lightly greased bowl, cover with a clean kitchen towel or plastic wrap, and let it rise in a warm place for 1–1 ½ hours, or until doubled in size.

Step 2: Prepare the Filling

1. In a medium bowl, combine the softened butter, brown sugar, cocoa powder, and cinnamon. Mix until it forms a smooth paste.

Step 3: Roll Out the Dough

1. Once the dough has risen, punch it down to release the air and transfer it to a lightly floured surface.
2. Roll the dough into a rectangle approximately 12×18 inches. Spread the chocolate-cinnamon filling evenly over the surface of the dough, leaving a ½-inch border around the edges.
3. Sprinkle the chocolate chips or chopped chocolate evenly over the filling.

Step 4: Roll and Slice the Rolls

1. Starting from the longer edge, tightly roll the dough into a log. Pinch the seam to seal.
2. Using a sharp knife or dental floss (for cleaner cuts), slice the log into 12 equal rolls.
3. Arrange the rolls in a greased 9×13-inch baking dish, leaving a bit of space between each roll.

Step 5: Second Rise

1. Cover the baking dish with a clean kitchen towel or plastic wrap and let the rolls rise for 30–45 minutes, or until puffed and touching each other.

Step 6: Bake the Rolls

1. Preheat your oven to 350°F (175°C).
2. Bake the rolls for 20–25 minutes, or until golden brown and cooked through. Avoid overbaking, as you want them to stay soft and gooey.

Step 7: Make the Topping (While Rolls Bake)

For Chocolate Glaze:

1. In a medium bowl, whisk together the powdered sugar, cocoa powder, milk, and vanilla extract until smooth. Adjust the consistency by adding more milk if needed.

For Cream Cheese Frosting:

1. In a medium bowl, beat the softened cream cheese and butter until smooth. Gradually add the powdered sugar and vanilla extract, mixing until creamy.

Step 8: Frost the Rolls

1. Once the rolls are out of the oven, let them cool for 5–10 minutes before spreading the chocolate glaze or cream cheese frosting over the top.

Step 9: Serve

1. Serve the rolls warm, and enjoy their gooey, chocolatey goodness. Store leftovers in an airtight container for up to 2 days, reheating before serving for the best texture.