Set the butter, eggs and cream cheese out to warm to room temperature. Place the milk in a small saucepan. Bring to a boil. The moment it reaches a boil, remove from heat. (This process is called scalding, and it ensures the milk doesn't affect the yeast's ability to rise. Don't skip!)
Pour the hot milk into the bowl of an electric mixer and add 1/2 cup butter, to bring the temperature down. Stir and allow the butter to melt completely. Then stir in the sugar. Touch the milk mixture to test the temperature. It should be close to luke warm. If it is not, add 1/2 cup flour and test again. Once it is just above room temperature, stir in the yeast and let it foam for approximately 10 minutes. (Too-hot liquid can kill yeast.)
Place the bread hook on the mixer and turn on low. Add the eggs, salt, and remaining flour up to 4 cups. Allow the mixer to "knead" the dough until it pulls away from the sides. Run the mixer for approximately 10 minutes to allow the dough to stretch and develop the gluten. If the dough seems too sticky after the first 2-3 minutes add an additional 1/4 cup flour. After 10 minutes, turn the mixer off. Cover the top with plastic, and allow the dough to rise until double in size, approximately 60-90 minutes in a warm kitchen.
For the Cinnamon Roll Filling:
Mix the brown sugar, softened butter, cinnamon, and nutmeg until smooth. Keep at room temperature until ready to use.
Dump the inflated dough out on a well-floured work surface. Fold into thirds and press flat. Then turn and fold into thirds again and press into a rectangle. Roll the rectangle out into a large 16 X 20 inch sheet.
Using a large flat spreader, spread the cinnamon filling over the sheet into a thin layer. Leave 1 1/2 inches bare (cinnamon-free) on one long edge. Be careful not to gouge holes in the dough. Starting at the cinnamon-covered long edge, roll the dough sheet tightly toward the uncovered edge to form a long tight log. Place a piece of parchment paper in a 9 X 13 inch baking dish. Then cut the log into 12 equal rolls. Tuck the loose end under each roll to secure it, and place them in the baking dish to rise.
Preheat the oven to 350 degrees F. Allow the rolls to rise for at least 30 minutes while the oven heats. Then bake for 20-25 minutes, until the edges are barely golden and the center of each roll is puffed high up.
For the Cream Cheese Frosting:
While the rolls are in the oven, beat the cream cheese, butter, vanilla, and powdered sugar together until completely smooth. The moment the rolls come out of the oven gently spread half the glaze over the tops and allow it to seep down into the cracks. Five minutes later, add more glaze if desired. Serve warm or at room temperature.
To prep ahead, make the dough the day before serving. Follow the instructions through cutting the rolls and placing them in the dish. Then cover the baking dish with plastic and refrigerate until morning. Set them out on the counter while the oven warms. Bake for approximately 30 minutes and glaze!