Proof the yeast in the warm milk for 10-15 minutes or until bubbly. Whisk in the sugar, butter, salt and egg. Stir in the flour until the dough comes together.
Knead the dough on a floured surface for a few minutes until it is smooth and elastic. Place in a greased bowl and let rise until double in size.
Punch the dough down and need a few times until smooth. Combine the 1/2 cup brown sugar and 1 tablespoon cinnamon.
Roll the dough into an 10 by 18 inch rectangle. Spread the 4 tablespoons of butter on the dough. Sprinkle with the cinnamon sugar mixture, and then the graham cracker crumbs, chocolate chips and marshmallows. Roll up tightly starting on the short edge.
Using thread or a very sharp knife, cut the log into 8 or 9 rolls. Place them in a greased 10 inch baking pan. Bake at 375 F for 15-16 minutes or until lightly browned.
Remove from the oven let cool while making the frosting. To make the frosting, cream the butter and cream cheese until smooth. Stir in the the vanilla, powdered sugar and enough of the milk to make a smooth frosting. Spread over slightly warm rolls