Gently warm 1 cup of whole milk until it's just warm to touch, about 110°F (43°C). In a bowl, whisk together the warm milk, ¼ cup of granulated sugar, and 2¼ teaspoons of active dry yeast. Let sit for 5 minutes until frothy. Melt ¼ cup of butter, whisk in with 2 eggs and 1 teaspoon of vanilla extract.

In a large bowl, combine 4 cups of all-purpose flour, ½ cup of unsweetened cocoa powder, and 1 teaspoon of salt. Gradually pour the wet mixture into the flour mixture, stirring until a soft dough forms.

Transfer the dough to a floured surface and knead for 5-7 minutes until smooth and elastic. Shape into a ball, place in a greased bowl, cover, and let rise in a warm area for about 1 hour.

Mix ½ cup of brown sugar, 2 tablespoons of ground cinnamon, and ¼ cup of melted butter until blended. Once the dough has risen, punch it down and roll out into a rectangle about 12x16 inches. Spread the filling evenly across the surface.

Starting from one long edge, roll the dough tightly into a log. Slice the log into 12 equal pieces using a sharp knife or dental floss.

Place the rolls in a greased baking dish, cover, and let rest for 30 minutes. Preheat oven to 350°F (175°C). Bake for 25-30 minutes until golden brown.

Let the rolls cool for 10 minutes in the dish. Mix 1 cup of sifted powdered sugar with milk or cream for glaze, drizzle over warm rolls before serving.