Warm the milk in a microwave-safe bowl for 45 seconds to 1 minute until it registers 115°F.

Sprinkle the yeast over the warmed milk in the stand mixer bowl. If using active dry yeast, add sugar and let sit until foamy for about 5 minutes.

Mix in melted butter, egg, and egg yolk on medium speed until well combined.

Stir in the flour and kosher salt until a dough begins to form.

Knead the dough on medium speed with a dough hook for 8 to 10 minutes, adding flour as necessary until it feels soft and slightly sticky.

Transfer the dough to a lightly greased large bowl, cover with plastic wrap and a warm towel, and let rise until doubled in size (about 1 to 1½ hours).

Dust a surface with flour, turn out the dough, and roll it into a 10 × 14-inch rectangle.

Spread softened butter over the dough, leaving a ¼-inch margin at one end. Mix brown sugar and cinnamon, sprinkle over the butter, and rub it in gently.

Starting from the short side without the margin, roll the dough tightly. Seal the edge by pinching it, cut off ½ inch from both ends, and compact the ends slightly.

Cut the dough into nine 1-inch slices using unflavored dental floss or a serrated knife.

Line a 9-inch round or square baking pan with parchment paper, place the rolls in the pan, cover with plastic wrap and a towel, and let rise until puffed and doubled (about 45 minutes to 1 hour).

Preheat the oven to 350°F.

Bake the rolls for 20 to 25 minutes until golden brown on the edges. Cool for 10 minutes.

In a stand mixer fitted with the whisk attachment, combine cream cheese, powdered sugar, butter, and vanilla, and beat until smooth and fluffy.

Spread the frosting over warm rolls and serve.