Dough ▢1 cup warm water 110–115°F ▢¾ cup buttermilk room temperature ▢4 tablespoons unsalted butter melted ▢½ cup sugar ▢3 tablespoons rapid rise yeast ▢2 large eggs ▢½ tablespoon salt ▢5-5½ cups bread flour Filling ▢⅔ cup granulated sugar ▢⅔ cup packed light brown sugar ▢4 tablespoons unsalted butter melted ▢3 tablespoons ground cinnamon Frosting ▢3 cups powdered sugar ▢4 ounces cream cheese softened ▢4 tablespoons unsalted butter softened ▢3-4 tablespoons milk or half-and-half, as needed ▢1 teaspoon vanilla extract
Make the dough: In the bowl of a stand mixer or large bowl using a wooden spoon, mix water, buttermilk, melted butter, sugar, and yeast. Allow to sit for 15 minutes. Add eggs and salt, then mix in flour one cup at a time. Mix for 5 minutes, then allow to rest for 10 minutes.
Meanwhile, prepare your filling. Mix granulated sugar, brown sugar, melted butter, and cinnamon together in a medium bowl. Set aside. Preheat the oven to 375°F. Grease a large baking dish or jelly roll pan (or a 9-x-13-inch baking dish if you are fine with your rolls touching).
On a lightly floured surface, roll dough into a 12-x-16-inch rectangle. Spread filling over the surface of the dough, leaving a ½-inch border all around. Roll the dough into a log starting at the long edge, making sure the seam is on the bottom.
Use a long piece of unflavored dental floss or sewing thread to cut the roll into 12 large rolls or 18 smaller rolls. Gently place the floss under the spot you wish to cut, then bring the floss up, cross it over the top, and pull the ends so it slices right through the dough. Place rolls cut side up in the prepared pan. Bake for 17–20 minutes.
While rolls are baking, mix all frosting ingredients together in a large bowl, starting with 3 tablespoons milk and adding more as needed to reach a spreadable consistency. When rolls come out of the oven, immediately spread a layer of frosting on warm rolls. Add another layer of frosting once cooled.