This is a ton of work.
Warm in a medium saucepan over low heat until it reaches 100-110F.
- 1 cup whole milk
Remove from the heat, vigorously combine yeast and 1/4 to 1 teaspoon sugar, and then set aside until foamy, about 5-15 minutes.
- one 1/4-ounce packet active dry yeast (2.5 teaspoons)
- 1/4 teaspoon granulated sugar (or follow directions on yeast packet)
Whisk in:
- 4 tablespoons unsalted butter, melted, plus more for the bowl
- 1 large egg yolk
- 1 1/2 teaspoons vanilla extract
In a stand mixer, whisk together:
- 1/4 cup granulated sugar
- 2 3/4 cups all-purpose flour, plus more if needed
- 3/4 teaspoon salt
- 1/2 teaspoon freshly grated nutmeg
Make a well in the center and pour in the yeast mixture. Mix on low speed with the dough hook until thick and slightly sticky. Knead on medium speed until the dough gathers around the hook, 6 minutes. (Add up to 2 more tablespoons flour if necessary.)
Remove the dough and shape into a ball. Butter the mixer bowl and return the dough to the bowl, turning to coat with butter. Cover with plastic wrap and let rise until doubled, 1 hour 15 minutes.
In a bowl, combine:
- 12 tablespoons unsalted butter, softened, plus more for the pan
- 1/2 cup granulated sugar
- 3 tablespoons ground cinnamon
On a lightly floured surface, roll the dough into a 12-by-14-inch rectangle with the longer side facing you. Spread with the softened butter, leaving a 1/2-inch border on the far long edge. Brush the unbuttered far edge with water. Roll the dough away from you into a tight cylinder and press on the long edge to seal. Cut the cylinder with a sharp knife to make 6 equal-size buns.
Place the buns cut-side down in a buttered 9-by-13 inch baking pan, leaving space between each.
Cover with plastic wrap and let rise until doubled, 40 minutes.
Preheat the oven to 325 F and bake the buns until golden brown, about 35 minutes.
Meanwhile, whisk together the glaze:
- 2 cups confectioners' sugar, sifted
- 1/3 cup heavy cream
- 4 tablespoons unsalted butter, melted
Transfer the buns to a rack and spoon the glaze on top while still warm.
Cool in the pan 15 minutes.