Proof the yeast by combining warm milk, a pinch of sugar, and yeast in a small bowl. Let sit 5-10 minutes until foamy.
Mix dry ingredients - whisk flour, cocoa powder, sugar, and salt in a large bowl.
Combine softened butter, egg, vanilla, red food coloring, warm buttermilk, and yeast mixture into the dry ingredients. Mix until a dough forms.
Knead dough for 8-10 minutes until smooth and slightly tacky.
First rise - place dough in an oiled bowl, cover, and let rise 1 to 1.5 hours until doubled.
Make the filling by mixing brown sugar and cinnamon together.
Roll out dough on a floured surface into a 12x16 inch rectangle. Spread with softened butter, then sprinkle cinnamon sugar evenly over it.
Roll and cut the dough tightly from the long side into 12 equal rolls using dental floss or a sharp knife.
Second rise - arrange rolls in a greased 9x13 inch dish, cover, and let rise 30-45 minutes.
Bake at 350°F (175°C) for 22-25 minutes until edges are set. Do not over-bake.
Make the glaze by beating cream cheese, powdered sugar, milk, and vanilla until smooth.
Frost and serve - spread glaze over warm rolls and enjoy immediately.