Make the dough: In a large bowl, whisk flour, yeast, sugar, and salt. Add warm milk, melted butter, egg, and vanilla. Mix until a shaggy dough forms.

Knead: Turn onto a lightly floured surface and knead 6–8 minutes until smooth and elastic. If sticky, dust with a little flour. The dough should be soft, not stiff.

First rise: Place in a greased bowl, cover, and let rise in a warm spot until doubled, about 60–90 minutes.

Make the filling: Stir soft butter with brown sugar, cocoa, cinnamon, and a pinch of salt to form a spreadable paste.

Roll out: Punch down the dough and roll into a 12x16-inch rectangle. Spread the filling evenly, then sprinkle on chocolate chips.

Shape: Starting from a long side, roll into a tight log. Trim the ends, then slice into 12 even rolls using dental floss or a sharp knife.

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

Bake: Preheat oven to 350°F (175°C). Bake 20–24 minutes, until lightly golden and just set in the center. Don’t overbake or they’ll dry out.

Make the icing: Whisk powdered sugar, cocoa, vanilla, salt, and milk until smooth and pourable.

Finish: Cool rolls for 10 minutes, then drizzle with icing. Serve warm.