Warm the milk: Heat 1 cup milk until warm to the touch, about 110°F. Stir in 2 1/4 teaspoons instant yeast and 1 tablespoon sugar. Let sit 5 minutes until slightly foamy.

Make the dough: In a large bowl, whisk 3 cups flour, 1/4 cup sugar, and 1 teaspoon salt. Add yeast mixture, 2 eggs, 1 teaspoon vanilla, and 6 tablespoons melted, cooled butter. Mix until a shaggy dough forms. Knead by hand or mixer, adding up to 1/2 cup more flour as needed, until smooth and slightly tacky, 6–8 minutes.

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

Make the filling: In a small bowl, mix 1/2 cup softened butter, 3/4 cup brown sugar, 2 tablespoons cocoa powder, 2 teaspoons cinnamon, 1 teaspoon espresso powder (optional), and a pinch of salt until spreadable.

Shape the rolls: Butter a 9x13-inch pan. Roll dough into a 12x16-inch rectangle. Spread filling evenly to the edges. Sprinkle 3/4 cup mini chocolate chips over the top. Roll up tightly from the long side. Trim ends, then slice into 12 even pieces.

Second rise: Arrange rolls in the pan, cover, and let rise until puffy, 30–45 minutes. For overnight, cover tightly and refrigerate up to 16 hours; bring to room temp 45–60 minutes before baking.

Bake: Preheat oven to 350°F (175°C). Bake 22–27 minutes until lightly golden on top and the center registers about 190°F. Don’t overbake.

Glaze: Whisk 1 cup powdered sugar, 1 tablespoon cocoa, a pinch of salt, 1/2 teaspoon vanilla, and 2–3 tablespoons milk until smooth and pourable. Spread over warm rolls.

Rest and serve: Let the glaze set 5–10 minutes. Serve warm and gooey.