Dough
1/2 C milk
8 Tb unsalted butter
1/2 C warm water (about 110 degrees)
1 envelope (about 2 1/4 teaspoons) dry active yeast
1/4 C sugar
1 large egg, plus 2 large egg yolks
1 1/2 tsp. salt
4-41/2 C all-purpose flour, plus more for dusting work surface
Filling
1 cup brown sugar, packed
3 tablespoons ground cinnamon
2-4 Tb butter, softened
Icing
4 oz cream cheese, at room temperature
1/4 C or less butter
1/2 tsp vanilla
1/2 Tb milk
2-2 1/2 C powder sugar
pinch of salt
Heat milk and butter in the microwave until butter melts - stir frequently. Remove from microwave and set aside until the mixture is lukewarm (about 100 degrees). Dissolve yeast in warm water with 1 Tb of the 1/4 C sugar. Let rest until bubbly, 5-10 minutes.
In a bowl of a standing mixer fitted with the paddle, mix together the yeast mixture, remaining sugar, egg, and yolks at low speed until well mixed. Add the salt, warm milk mixture, and 2 cups of the flour and mix at medium speed until thoroughly blended, about 1 minute. Switch to the dough hook, add another 2 cups of flour. and knead at medium speed (adding up to 1/4 C flour, 1 Tb at a time, if necessary) until the dough is smooth and freely clears the sides of the bowl, about 10 minutes. Scrape the dough onto a lightly floured work surface. Shape the dough into a round, place it in a very lightly oiled large bowl, and cover the bowl with lightly greased plastic wrap. Leave in a warm, draft free spot until doubled in bulk. 1 1/2 - 2 hours.
After the dough has doubled in size turn it out onto a lightly floured surface. Roll dough into a 16x21 inch rectangle. Mix the cinnamon/sugar for the filling. Spread dough with 1/4 cup butter and sprinkle evenly with sugar/cinnamon mixture. Roll up dough tightly and moisten top border with water and seal the roll. Cut into 12 rolls with thread or floss. Place rolls in a lightly greased 9x13 inch baking pan. Cover with plastic wrap and let rise until nearly doubled, about 1 1/2 - 2 hours.
When doubled, preheat the oven to 350 and bake until golden brown 25-30 minutes. Invert the rolls onto a wire rack to cool 10 minutes. Turn the rolls upright and ice. Meanwhile, mix all ingredients for icing together. Spread frosting on warm rolls before serving.
Adapted from The Best New Recipe (Cooks Illustrated) and Allrecipes.com with Cream Cheese Icing from Kelsey Heaps