1. Bloom the yeast: In a large bowl, combine warm milk, 1 tablespoon sugar, and yeast. Let sit for 5-10 minutes until foamy.
2. Make the dough: Add the remaining ¼ cup sugar, ½ cup softened butter, eggs, salt, and 3 cups of flour to the yeast mixture. Mix until just combined. Gradually add the remaining 1 cup of flour, mixing until a soft dough forms. Knead on a lightly floured surface for 5-7 minutes until smooth and elastic.
3. First rise: Place dough in a lightly greased bowl, cover, and let rise in a warm place for 1-1.5 hours, or until doubled in size.
4. Prepare the filling: While the dough rises, mix together the cinnamon and 2 tablespoons of the reserved softened butter.
5. Assemble the rolls: Punch down the risen dough. Roll it out on a lightly floured surface into a large rectangle (about 12×18 inches). Spread the cinnamon-butter mixture evenly over the dough, leaving a small border.
6. Roll and cut: Tightly roll the dough lengthwise. Cut the log into 12 equal slices.
7. Second rise: Place the rolls cut-side up in a greased 9×13 inch baking pan. Cover and let rise for another 30-45 minutes.
8. Bake: Preheat oven to 375°F (190°C). Bake for 20-25 minutes, or until golden brown.
9. Make the frosting: While rolls bake, beat together softened cream cheese, ¼ cup softened butter, vanilla extract, and powdered sugar until smooth and creamy.
10. Frost: Let the cinnamon rolls cool slightly in the pan, then spread the frosting over the warm rolls.