Heat milk in small sauce pan to 90º – 95ºF. Remove and add yeast, whisk until dissolved and set aside.
Mix sugar, butter, salt, cinnamon, eggs and flour in large bowl until smooth.
Slowly combine with milk mixture, stir until dough pulls from bowl easily.
Knead dough on a lightly floured surface for 5 to 10 minutes.
Place dough in a large bowl and cover with plastic wrap. Let rest for 10 minutes or until doubled in size.
Coat bottom and sides of a 9 x 13 inch pan with butter.
Knead dough on a floured surface into a 15 x 10 inch rectangle.
Spread cinnamon smear over dough, roll dough together.
Cut into 1 inch slices, quarter each slice and place pieces close together in pan.
Cover the pan and let rise in a warm place until doubled in size (about 45 minutes).
Preheat oven to 350ºF.
Bake for 30 minutes or until golden brown.
Drizzle with icing and serve warm.
Cream together margarine, cinnamon and brown sugar.
Add eggs one at a time mixing well. Place in refrigerator until ready to use.
Mix milk, confectioners’ sugar, softened butter and vanilla extract in a bowl until smooth.
Drizzle over warm bun.