In a large mixing bowl, dissolve yeast in warm water. Let stand 10 minutes for it to foam up. Add ¼ cup of the granulated sugar, 2 tablespoons of the softened butter, sour cream, salt, and egg to the yeast mixture. Beat with a mixer with whisk attachment at medium speed until smooth.
Leaving ½ cup of flour aside, lightly spoon 3 cups of flour into a measuring cup 1 cup at a time, level off with the flat edge of a knife, and add to the yeast mixture, beating until smooth each time until a soft dough forms. Continue with a stand mixer and switch to a dough hook attachment on medium-low speed (or knead dough by hand on a floured surface). Knead dough, adding 1 spoonful of flour at a time until dough is smooth and elastic and only slightly tacky to the touch, about 2 to 3 minutes in a mixer or 10 minutes by hand.
Place dough in a large bowl coated with cooking spray, turning to coat top of the dough to help it rise. Cover with a tea towel and let rise in a warm place (85 F) for 1 hour or until doubled in size. (This can be done in the oven with a casserole dish filled with steaming water on the bottom rack and the dough on the top rack.) Gently press the dough. If indentation remains, the dough is ready. Punch dough down with your fist, cover, and let rest 5 minutes.
When the dough is ready, mix together cinnamon, ¾ cup of the granulated sugar, and 2 tablespoons of the orange rind in a small bowl. Roll out dough on a lightly floured surface to about 1/4-inch thick and in a slightly rectangular shape. Evenly spread 8 tablespoons (1 stick) of the softened butter across the surface of the dough, all the way to the edges, then evenly pour the cinnamon and sugar mix across butter layer. Starting at the longest side, roll the dough up into a log. Cut log into 16 rolls and place cut-side up in two greased 9-inch round cake or pie pans. Cover with a tea towel and let rise 30 minutes or until doubled in size. At this point, if you’re wanting extra-gooey rolls, pour half and half evenly across the top of rolls, letting it soak down to the bottom of the pan. If you prefer your rolls to be a bit more bread-like, skip that step. Bake uncovered at 350 F for 25 minutes or until golden brown.
In a medium mixer bowl, cream together remaining 4 tablespoons butter, cream cheese, 2 tablespoons orange zest, and orange juice until smooth. Slowly add the powdered sugar, then beat on high until smooth. Frost rolls while they’re still warm (or if not eating right away, warm up refrigerated frosting a bit in the microwave and stir).
To make the rolls ahead of time, follow the recipe until just before the second rise time. Place in the fridge, and pull out within 24 hours. Allow to rise before baking. Frosting can be prepared ahead and stored covered in the fridge for up to a week.
Per serving: 336 calories, 13 grams fat (8 grams saturated fat), 46 milligrams cholesterol, 239 milligrams sodium, 51 grams total carbohydrates, 2 grams fiber, 4.5 grams protein.