Step 1: Pour warm milk into a large bowl and sprinkle yeast over the surface. Let it sit for about 2 minutes until the yeast becomes foamy.

Step 2: Stir in sugar, softened butter, salt, and egg until combined.

Step 3: Add flour one cup at a time, mixing until a soft, slightly sticky dough forms.

Step 4: Knead by hand for 10 minutes or with a stand mixer for 6 to 8 minutes until dough is smooth and elastic.

Step 5: Place dough in an oiled bowl, cover with plastic wrap, and let rise at room temperature for 1 hour or until doubled.

Step 6: Mix brown sugar and cinnamon for the filling. Punch down dough and roll into a 16x12 inch rectangle.

Step 7: Spread softened butter over dough, sprinkle with cinnamon sugar mixture, then tightly roll into a log.

Step 8: Cut log into 12 equal rolls and arrange cut-side up in a parchment-lined 9x13 inch baking dish.

Step 9: In a saucepan over medium heat, melt butter and brown sugar, stirring until smooth. Remove from heat and stir in cream, vanilla, and salt.

Step 10: Pour warm caramel over rolls, cover loosely, and let rise for 30 to 45 minutes until puffy.

Step 11: Preheat oven to 350 degrees F and bake rolls uncovered for 22 to 25 minutes until golden brown and caramel is bubbling.

Step 12: Let rolls cool in the pan for 5 minutes before serving warm.