Activate the yeast: In a large bowl, whisk warm milk, yeast, and 1 tablespoon of sugar. Let sit 5–10 minutes until foamy.

Mix the dough: Add remaining sugar, egg, egg yolk, and melted butter. Whisk to combine. Stir in 3 cups flour and the salt. Mix until a shaggy dough forms.

Knead: Turn onto a lightly floured surface and knead 6–8 minutes, adding up to 1/4 cup more flour as needed. The dough should be soft and slightly tacky, not sticky.

First rise: Place dough in a greased bowl, cover, and let rise in a warm spot until doubled, about 1–1.5 hours.

Make the filling: Stir soft butter, brown sugar, cinnamon, vanilla, and a pinch of salt into a spreadable paste. Prep any flavor add-ins now.

Roll and fill: Punch down the dough. Roll into a 12x16-inch rectangle. Spread filling to the edges, leaving a thin border on one long side.

Add flavor: Sprinkle your chosen add-ins evenly over the filling. Press them lightly so they stick.

Roll tightly: Roll from the long edge toward the clean border. Seal the seam by pinching gently.

Slice: Trim the ends if uneven. Cut into 12 rolls using a sharp knife or dental floss for clean cuts.

Second rise: Arrange in a greased 9x13-inch pan, leaving a little space between rolls. Cover and let rise until puffy, 30–45 minutes.

Bake: Preheat to 350°F (175°C). Bake 20–25 minutes, until lightly golden and centers read about 190°F or feel set when tapped.

Glaze: Beat cream cheese, butter, powdered sugar, vanilla, salt, and milk until smooth. Spread over warm rolls.