Prepare dough as directed except mix in cocoa with the first addition of flour.
Divide dough in half.
Roll each half into rectangle, 15x9 inches.
Spread each with 2 tablespoons butter.
Mix sugar and cinnamon; sprinkle half the mixture over each rectangle.
Roll up, beginning at wide side.
Pinch edge of dough into roll to seal well.
Stretch roll to make even.
Cut each roll into 15 slices.
Place slightly apart in 2 greased baking pans, 13x9x2 inches, or in greased muffin cups.
Let rise until double.
Bake 25 to 30 minutes.
While warm, frost rolls with Icing.