1. Make the Dough: In a large bowl, whisk together warm milk, granulated sugar, and yeast. Let it sit for 5-10 minutes until foamy.
2. Add softened butter, eggs, salt, and 2 cups of the flour to the yeast mixture. Mix until combined.
3. Gradually add the remaining 2 cups of flour, mixing until a soft dough forms. If the dough is too sticky, add a little more flour, 1 tablespoon at a time.
4. Turn the dough out onto a lightly floured surface and knead for 5-7 minutes until smooth and elastic.
5. Place the dough in a lightly greased bowl, cover with plastic wrap, and let it rise in a warm place for 1-1.5 hours, or until doubled in size.
6. Prepare the Filling: While the dough rises, cream together softened butter, brown sugar, and cinnamon until well combined.
7. Assemble the Rolls: Once doubled, punch down the dough and turn it out onto a lightly floured surface. Roll it into a large rectangle, about 12×18 inches.
8. Spread the cinnamon-sugar filling evenly over the dough, leaving a small border along one long edge.
9. Starting from the long edge with the filling, tightly roll up the dough.
10. Cut the roll into 12 equal slices.
11. Place the rolls, cut-side up, in a greased 9×13 inch baking dish.
12. Cover the dish and let the rolls rise again for 30-45 minutes until puffy.
13. Preheat oven to 375°F (190°C) during the final proofing time.
14. Bake for 20-25 minutes, or until golden brown and cooked through.
15. Make the Frosting: While the rolls bake or cool slightly, beat together softened cream cheese and butter until smooth. Beat in vanilla extract.
16. Gradually add powdered sugar and milk, beating until you reach a smooth, spreadable consistency.
17. Frost the warm cinnamon rolls generously.