Combine the milk, orange juice, and yeast in a glass measuring cup, stirring to dissolve the yeast. Let bloom for 5 minutes, until foamy.
½ cup milk, ½ cup orange juice, ¼ ounce active dry yeast
Make the dough: In the bowl of a stand mixer fitted with the paddle attachment, combine the flour, sugar, butter, eggs, orange zest, and salt. Mix until just combined.
4 cups all-purpose flour, ¼ cup granulated sugar, ¼ cup unsalted butter, 2 large eggs, 1 teaspoon orange zest, ½ teaspoon kosher salt
Add the milk mixture and beat on low for 1-2 minutes, or until blended. Switch to the dough hook attachment, increase speed to medium-low, and beat for 5 minutes, or until the dough is smooth, soft, and slightly sticky.
Spray the inside of a glass bowl with nonstick spray, then place the dough inside, flipping to coat the ball. Cover the bowl, place it in a warm place, and allow the dough to rise (it should double in size) for 45-60 minutes.
While the dough rises, make the filling. Mix the sugar, softened butter, orange zest, and cinnamon in a small bowl until smooth.
¾ cup granulated sugar, ½ cup unsalted butter, 2 tablespoons orange zest, ½ tablespoon ground cinnamon
Once doubled in size, punch the dough down. Turn the dough out onto a lightly floured surface. Roll it into a 20x14-inch rectangle, about ¼ inch thick.
Spread the filling in a thin, even layer over the dough, leaving a 1-inch gap at one long edge. Roll up the dough, jelly roll style, starting at the long end.
Grease a 9x13-inch baking pan. Use a piece of unflavored dental floss to cleanly cut the dough log into 12 large rolls and place side-by-side in the prepared baking pan. Cover the baking pan and allow the rolls to rise for 30-45 minutes, or until doubled in size.
While the rolls are rising, preheat oven to 350°F.
Once doubled in size, bake the rolls for 20-25 minutes, or until lightly golden brown and 190°F internally. Remove from the oven, and cool slightly.
While the rolls bake, make the frosting. In the bowl of a stand mixer fitted with the paddle attachment, beat the powdered sugar, cream cheese, softened butter, orange juice, and orange zest together until smooth.
2 cups powdered sugar, 4 ounces cream cheese, 3 tablespoons unsalted butter, 3 tablespoons orange juice, 2 teaspoons orange zest
Spread frosting onto the warm rolls and serve.