In a large bowl, combine warm milk, melted butter, sugar, and yeast. Whisk in the egg until combined.

Add 4 cups of flour and salt. Mix with a dough hook or by hand until a soft dough forms. Knead for 5 to 7 minutes until smooth and elastic.

Place dough in a greased bowl, cover with a damp cloth, and let rise in a warm place for 60 to 90 minutes or until doubled in size.

Punch down the dough and turn it out onto a floured surface. Roll into a 12x18 inch rectangle.

Spread 1/3 cup softened butter over the dough. In a small bowl, mix brown sugar and cinnamon, then sprinkle evenly over the butter.

Roll the dough tightly from the long edge to form a log. Cut into 12 even slices using a serrated knife or dental floss.

Place rolls in a greased 9x13 inch baking pan. Cover and let rise for another 30 to 45 minutes.

Preheat oven to 350°F (175°C). Bake for 20 to 25 minutes or until lightly golden brown.

While rolls bake, beat cream cheese, 1/4 cup butter, powdered sugar, and vanilla until smooth. If desired, divide frosting and tint with pastel food coloring.

Spread the frosting over the cinnamon rolls while they are still warm but not hot.