Dissolve the yeast in the warm milk in a large bowl. Mix in the sugar, margarine, salt, and eggs. Add flour and mix well. Knead the dough into a large ball, using your hands dusted lightly with flour. Put in a bowl, cover and let rise in a warm place about 1 hour, or until doubled in size.
After the dough has doubled in size turn it out onto a lightly floured surface, cover and let rest for 10 minutes. In a small bowl, combine brown sugar and cinnamon.
Roll dough into a 16×21 inch rectangle. Brush dough with melted butter, then sprinkle with sugar/cinnamon mixture. Roll up dough starting along the long side and cut into 12 rolls. Place rolls in a lightly greased 9×13 inch baking pan. Cover and let rise until nearly doubled, about 30 minutes. Meanwhile, preheat oven to 350 degrees F.
Bake rolls in preheated oven until golden brown, about 20 minutes. While rolls are baking, beat together cream cheese, 1/4 cup butter, confectioners’ sugar, vanilla extract and salt. As soon as rolls come out of the oven, remove them from the pan. Spread any filling that has seeped out over the top and then spread frosting on rolls before serving.