In a large bowl, whisk together hot roll mix and included yeast, sugar, and cinnamon. Stir in 1 cup warm water, egg, and butter until combined. Turn out dough onto a heavily floured surface; generously sprinkle flour onto dough. Knead until a smooth, slightly sticky dough forms, about 5 minutes, adding flour as needed. Cover and let stand for 5 minutes.
On a lightly floured surface, roll dough into an 18×11-inch rectangle. Spray a 10-inch cast-iron skillet with cooking spray.
For filling:
In a small bowl, whisk together sugar, cocoa, and cinnamon. Spread butter onto dough; sprinkle sugar mixture onto dough. Starting at one long side, roll up dough into a log, pinching seam to seal. Using a serrated knife, cut log into 9 (2-inch-thick) slices. Place slices, cut side up, in prepared pan. Cover with plastic wrap, and let rise in a warm, draft-free place (75°) until doubled in size, 30 to 45 minutes.
Preheat oven to 375°.
Bake until golden brown and rolls are cooked through, 15 to 20 minutes, loosely covering with foil to prevent overbrowning if needed. Let cool on a wire rack for 30 minutes.
Spread Cinnamon-Cream Cheese Frosting onto warm rolls. Garnish with cinnamon, if desired. Serve warm.
Cinnamon-Cream Cheese Frosting
In a large bowl, beat cream cheese with a mixer at medium until smooth. Beat in milk, cinnamon, and salt until smooth, stopping to scape sides of bowl. Add confectioners’ sugar, beating on medium-low until smooth, stopping to scrape sides of bowl. Use immediately.
Notes
*We used Pillsbury Hot Roll Mix.
Recipe by Southern Cast Iron at https://southerncastiron.com/chocolate-cinnamon-rolls/