Warm the milk to about 110°F. In a small bowl, stir together the warm milk, yeast, and a pinch of sugar. Let it sit for 5–7 minutes until foamy.

In the bowl of a stand mixer (or a large bowl if kneading by hand), combine the melted butter, sugar, egg, and salt. Add the foamy yeast mixture.

Gradually add 3 cups of flour, mixing on low with the dough hook until the dough begins to pull away from the bowl. If it’s too sticky, add up to 1/2 cup more flour.

Knead for about 5–7 minutes in the mixer until smooth and elastic.

Lightly oil a bowl and place the dough inside, turning once to coat. Cover with a clean kitchen towel and let rise in a warm spot for about 1 to 1 1/2 hours, until doubled in size.

While the dough rises, toast the walnuts in a dry skillet over medium heat for 4–5 minutes, stirring often, until fragrant. Cool and chop.

In a small bowl, mix the softened butter, brown sugar, and cinnamon into a spreadable paste.

Punch down the risen dough and turn it out onto a lightly floured surface. Roll into a large rectangle, about 16x12 inches.

Spread the cinnamon-brown sugar butter evenly over the dough, leaving a 1/2-inch border. Sprinkle the chopped walnuts evenly over the filling.

Starting from a long edge, roll the dough tightly into a log. Pinch the seam to seal.

Using a sharp knife or dental floss, cut the log into 12 even rolls. Place rolls in a greased 9x13-inch baking pan, leaving a little space between each.

Cover the pan loosely and let the rolls rise for 30–45 minutes, until puffy.

Preheat oven to 350°F. Bake rolls for 20–25 minutes, until golden brown. If the tops brown too quickly, tent with foil.

While the rolls finish, beat the cream cheese and butter until smooth. Add powdered sugar, vanilla, and a pinch of salt. If too thick, add 1 tablespoon of milk at a time to reach a spreadable consistency.

Let the rolls cool for 5–10 minutes, then spread the cream cheese frosting over the warm rolls.

Garnish with extra chopped walnuts if desired.