Instructions:
- Proof the yeast in warm milk with 1 tablespoon of sugar; let stand until foamy (5–10 minutes).
- In a stand mixer bowl, whisk together the remaining sugar, 4 ½ cups flour, and salt. Add the yeasted milk mixture and eggs; mix on low until just combined.
- Knead with the dough hook for 5 minutes. Gradually add the softened butter, one cube at a time, kneading until fully incorporated. Continue kneading on medium speed until the dough is smooth, elastic, and pulls cleanly away from the sides (about 8–10 minutes).
- Place the dough in a lightly oiled bowl, cover, and let rise in a warm spot until doubled in size (approx. 1.5 to 2 hours).
- Prepare the topping: In a separate bowl, combine 1 ½ cups flour, ¾ cup sugar, cinnamon, and cocoa (if using). Cut in the cold butter using a pastry blender or your fingers until the mixture resembles coarse meal. Divide into two halves; keep one plain and mix the other with cocoa powder. Chill until needed.
- Gently deflate the risen dough. Divide into 12 equal portions. Roll each portion into a tight ball and place on lined baking sheets, leaving 2 inches between each roll. Let rest briefly (15 minutes).
- Roll the topping mixture out between two sheets of parchment paper until 1/8-inch thick. Cut the topping into 12 circles, slightly larger than the dough balls. Gently place one topping circle over each dough ball.
- Use a knife or bench scraper to lightly score the topping in a crosshatch or spiral pattern to create the shell effect.
- Cover and allow the shaped rolls to proof again until puffy (approx. 45–60 minutes).
- Preheat oven to 375°F (190°C). Bake for 18–22 minutes, or until the bread beneath the topping is golden brown. Cool on a wire rack.