Dissolve yeast in warm milk with pinch of sugar until foamy
Mix flour, cocoa powder, sugar, and salt in large bowl
Combine buttermilk, softened butter, eggs, red food coloring, and vanilla
Add wet ingredients to dry ingredients along with yeast mixture
Knead until smooth, elastic dough forms with vibrant red color
Place dough in greased bowl, cover and rise 1 hour until doubled
Mix softened butter, brown sugar, cinnamon, and cocoa for filling
Roll risen dough into large rectangle on floured surface
Spread cinnamon filling evenly, leaving small border
Roll tightly from long side, pinching seam to seal
Cut into 12 equal pieces using sharp knife or dental floss
Place cut rolls in prepared baking dish with space between
Cover and rise 45 minutes until puffy and touching
Bake at 350°F for 25-30 minutes until golden on top
Cool slightly while preparing cream cheese frosting
Beat cream cheese, butter, powdered sugar, vanilla and milk until smooth
Drizzle frosting over warm rolls and serve immediately