Activate Yeast: Combine 1 cup of warm milk and 2¼ teaspoons of active dry yeast in a bowl. Let sit for 5-10 minutes until frothy.

Mix Dough: Sift together 4 cups of all-purpose flour, ⅓ cup cocoa powder, ½ cup brown sugar, and 1 teaspoon salt. Add yeast mixture, 1 egg, and ⅓ cup melted butter, mixing until smooth.

First Rise: Let the dough rise in a greased bowl covered with a damp cloth for 1½ to 2 hours until doubled.

Prepare Filling: Mix together ½ cup brown sugar, ¼ cup cocoa powder, 1 tablespoon ground cinnamon, and 1 teaspoon vanilla extract.

Shape Rolls: Roll out the dough into a rectangle, spread ⅓ cup softened butter, sprinkle filling, roll tightly and slice into 9-11 pieces.

Second Rise: Place rolls in a greased dish, cover, and let rise for 30-60 minutes.

Bake: Preheat oven to 350°F (180°C) and bake for about 20 minutes until golden brown.

Glaze: Prepare glaze by whisking together 1 cup powdered sugar, 2 tablespoons cocoa powder, and 3-4 tablespoons heavy cream. Drizzle over warm rolls.