Preheat oven to 425 degrees F and grease a 9 by 13 baking dish.
Mix together all the dry dough ingredients. Then add the buttermilk and butter and knead a few times to bring dough together.
Pat out the dough into a large rectangle measuring 12" by 18" and about 1/2" thick.
Mix together the brown sugar and orange zest in a small bowl. Using a pastry brush, brush the 1/2 cup melted butter over the entire rectangle.
Sprinkle the mixture over the dough. Roll up the dough from the long side.
Slice into 12 rolls about 1 1/2" thick and place in prepared baking dish. Bake for about 25-30 minutes until golden brown around the edges.
Mix together glaze ingredients and pour over the rolls while they are still warm.
Swap 1 Tbsp cinnamon for the 2-3 Tbsp orange zest in the filling and use milk instead of orange juice for the icing. If desired, you can also add 1 1/2 cups raisins to the filling for cinnamon raisin rolls.
There are lots of ways to customize these orange rolls. Here are some ideas of additions you can make to the filling:
add 1 1/2 cups dried cranberries or dried blueberries
add 2 cups fresh raspberries or blackberries
Channel the British classic Chelsea buns with just a few swaps!Add 2 tsp cinnamon, 1/2 cup dried cranberries, 1/2 cup golden raisins, 1/2 cup chopped apricots to the filling. Brush about 1 Tbsp of warmed apricot jam mixed with 1 tsp water over the top of the warm rolls.For a glaze, combine 1 cup powdered sugar with 1 Tbsp orange zest with 2 Tbsp water and drizzle over the rolls.