Preheat oven to 350° Fahrenheit and lightly grease a 9x4-inch loaf pan.
Add the all purpose flour, plain Greek yogurt, and 2 tablespoons of sugar to a large bowl. Mix together until a dough forms. If the dough seems dry, add an additional 1-2 tablespoons of Greek yogurt. The dough might seem dry, but just use enough Greek yogurt until it can be formed into a ball (you’ll have to get your hands dirty here!).
Lightly flour a kitchen surface and roll the dough out into a 9x13-inch rectangle. Spread the softened butter on top of the dough, then sprinkle the dough evenly with ½ cup sugar and the cinnamon.
Carefully take the long end of the dough and roll it into a tight log. Slice the log into 8-9 cinnamon rolls, each about 2 inches thick.
Then, place the cinnamon rolls into your prepared baking pan and bake for 30-35 minutes, or until lightly golden brown on top.
Remove the protein cinnamon rolls from the oven and let them cool for a few minutes while you make the frosting.
Add all frosting ingredients to a bowl and use either a hand or stand mixer to whip everything together until smooth. Top the cooled cinnamon rolls with the protein frosting and enjoy!