Butter a 9x13 inch pan to prevent sticking.
In a large mixing bowl, whisk together flour, cocoa powder, sugar, yeast, and salt.
Combine water and butter, heat until warm, then add to dry ingredients with the egg and mix well.
Add flour gradually until dough forms a ball, knead for 4-6 minutes until smooth and elastic.
Cover the dough and let it rise in a warm place for about 10 minutes.
Roll out the dough into a rectangle, spread softened butter, and sprinkle with cinnamon and sugar.
Roll the dough tightly, seal the seam, and cut into 12 equal sections. Place in the prepared pan.
