Measure out the 2C buttermilk in a large measuring cup, and then remove 2T of the buttermilk and substitute by adding in the 2T of white vinegar. Mix the buttermilk, vinegar, vegetable oil, sugar, and red food coloring in a pot. Heat the mixture until just before the boiling point. Turn off the heat and leave to cool for 45 minutes to an hour. Meanwhile, sift together the 3 3/4C AP flour with the 1/4C unsweetened cocoa powder, and set it aside. When the milk mixture is warm (but not hot), sprinkle in the package of yeast. Let it sit for a minute or two, and then add in the sifted flour-cocoa powder. Stir the mixture and cover, and then let it rise for at least an hour.
After rising for an hour, add in 1/2C AP Flour, baking powder, baking soda, and salt. Stir the mixture together. Refrigerate the dough overnight to help it become firm and better for presentation.
The next day, sprinkle a rolling surface generously with flour. Take the dough and form a rough rectangle, and then roll the dough out to about 1/4-1/2inch thick (depending on your preference), while making sure to maintain a rough rectangular shape from before. Once rolled out, proceed to the filling step.
Smear or spread on the amount of butter you prefer over your rectangular dough, either one to two cups. I used 1C of the very soft butter (but some people prefer melted, I find that melted butter is more messy and harder to work with). Now, sprinkle 1C of sugar over the butter, followed by a generous sprinkling of cinnamon (this is up to how much cinnamon you like, we like a lot).
Now, starting at the opposite end, begin rolling the dough in a neat line toward you. Keep the roll relatively tight as you go. Next, pinch the seam of the roll to seal it. Spray a 13×9-baking pan with Pam, and set it aside. Then, begin cutting the rolls into approximately 10-12 thick round rolls and place them into the prepared buttered pans. Let the rolls rise for an hour.
Preheat the oven to 375 degrees.
Bake the cinnamon rolls for 15-20 minutes or until light golden brown.