For the dough; fit a heavy-duty stand mixer with the dough hook.
Place 4 cups flour in the stainless steel bowl; set aside.
Proof the yeast with 2 teaspoons sugar in 1/2 cup warm water for about 8-10 minutes or until foamy.
Meanwhile in a microwave-safe bowl place the milk with butter cubes, salt and sugar; microwave on high until just slightly warmed (about 1 minute or a little more the butter does not have to be completely melted) stir to dissolve the sugar and salt.
Add the mixture to the bowl along with the egg.
When the yeast is foamy add to the bowl.
Start kneading adding in more flour as needed to create a soft smooth dough (kneading will take about 8-10 minutes).
Remove to a lightly floured surface, cover with a clean tea towel and allow the dough to rest for 5 minutes.
Shape the dough into a ball and place into a greased bowl; cover and rise for about 1-1/2 hours or until doubled (the rising time will vary depending on how warm your kitchen is).
Punch down the dough and allow to rest in bowl for 5 minutes.
In a small bowl mix together the brown sugar with cinnamon.
Transfer to a floured surface, roll into about 18 x 13-inch rectangle with short end facing you to make rolling up easier (I just spread out the dough using my hands, the measurments do not have to be exact).
Spread the softened butter over the dough (you can use more than 1/2 cup buter if desired, I usually do!).
Sprinkle the brown sugar/cinnamon mixture evenly over the butter, sprinkle with raisins and/or nuts if using.
Starting at the short end roll up the dough as tightly as possible (the dough will spread out even more while rolling).
Pinch the long seam together as best you can, you might also want to slice a small piece off both ends to even off the roll).
Using a serrated knife slice log into two even halves, then slice each half into 6 even slices (this will give you 12 pieces, although I sometimes get less).
Generously butter two 9-inch round cake pans (or use one 13 x 9-inch pan and place 3 rounds across, 4 rounds down in the pan).
In each round cake pan place 5 dough rounds around the pan and 1 dough round in the middle placing cut-side down.
Cover with a clean tea towel and allow to rise in a warm place until doubled (this may take about 1 to 1-1/2 hours or more depending on the temperature of your kitchen).
Set oven to 375 degrees F.
Bake until browned about 25 minutes.
Cool the buns slightly then drizzle the icing over the warm buns.