2 cups milk
2 1/2 tablespoons sugar
2 (1/4 ounce) packages active dry yeast (or 4 1/2 teaspoons)
5 to 5 1/2 cups all purpose flour, divided
1 tablespoon salt
6 tablespoons unsalted butter, melted
Vegetable oil to grease bowl
8 tablespoons salted butter, softened
3/4 cup sugar
2 tablespoons ground cinnamon
2 teaspoons vanilla powder (optional)
1/2 cup toasted chopped pecans or walnuts (optional)
1/2 cup dried cherries; currants; cranberries; or raisins (optional)
2 cups confectioners' sugar
1/4 cup milk
1 teaspoon vanilla extract
To make the rolls - Combine the milk and sugar in a small saucepan; whisk together. Cook over medium heat, whisking occasionally until the sugar is dissolved and the milk has reached 110 degrees. (Use an instant-read thermometer to test the temperature.) Pour the warm milk mixture into a small bowl; add the yeast and whisk to combine. Set aside until foamy and creamy, about 5 to 10 minutes.
Place 5 cups of flour and the salt in the bowl of a stand mixer. Using the dough hook attachment, mix on low speed for 30 seconds to combine. Add the yeast mixture and melted butter, increase speed to medium-high and continue mixing until the dough is smooth and elastic, about 4 to 5 minutes. After the first 2 minutes of mixing, if the dough seems too sticky, add the remaining flour, 1 tablespoon at a time until the dough cleans the sides of the bowl. The dough may continue to stick slightly to the bottom of the bowl. (The dough should register approximately 80 degrees on an instant-read thermometer.) Using a dough scraper or a silicone spatula, scrape the dough out onto a lightly floured silicone rolling mat; knead until satiny smooth, about 1 minute.
Place dough in a lightly oiled mixing bowl; turn the dough over to oil all sides. Cover with oiled plastic wrap and allow to rise until doubled in size, about 1 hour.
Punch down (deflate) the dough, then turn out onto a lightly floured silicone mat. Roll the dough into a rectangle 15 inches in length and about 1/4 inch thick.
To make the filling - Spread the softened butter over the surface of the dough. Combine the sugar, cinnamon, and vanilla powder; whisk together, then sprinkle evenly over the butter. Cover the entire surface, but leave 1/2 inch border on both long sides. Sprinkle evenly with nuts and dried fruit, if desired.
Starting at the long side nearest you, tightly roll the dough into a log as you would for a jelly-roll, then pinch the seams to seal. Place on a parchment paper lined sheet pan, seam side down; cover loosely with plastic wrap. Refrigerate for about an hour (or place in the freezer for about 15 minutes).
Cut the chilled log into 12 evenly sized pieces, each about 1 1/4 inches thick. (For best results use a sharp serrated or electric knife.) Place on an oiled baking sheet, cover loosely with oiled plastic wrap, and allow to rise until almost doubled in size, about 30 minutes.
Preheat oven to 425 degrees F. Bake in the center of the oven until light golden brown, about 15 minutes. Rotate the pan halfway through the baking time.
To make the glaze - In a medium bowl, combine the confectioners' sugar, milk, and vanilla extract; whisk together until smooth. Allow the cinnamon rolls to cool for 2 to 3 minutes after baking, then pour the glaze over the top of the rolls; serve immediately.