Scald milk and pour into a large bowl. Add sugar, salt and butter. Stir until butter melts.
Dissolve 1 tsp sugar in 1/2 cup lukewarm water. Sprinkle in yeast. Let stand for 10 minutes.
Stir yeast mixture with a fork and add to milk mixture. Stir in egg.
Beat in 2 cups flours. Beat vigorously by mixer about 6 min until shiny and smooth.
With dough blade on mixer, gradually add 2 1/2 to 3 cups more flour.
Turn dough onto a floured surface and knead for about 5 minutes. Shape into a smooth ball and placed into a greased bowl. Cover with plastic wrap and let rise for about 90 min in a warm space until double in size.
Punch the dough and cut in half.
Roll out dough into two 9x12 rectangles onto a floured surface.
Mix butter, sugar and cinnamon together in a bowl and brush onto dough.
Roll up like a jelly roll and cut into 1-2 inch slices (for big cinnamon buns roll up from short side).
Place slices cut side down into greased pan. Cover and let rise for about 45 minutes or until double in size.
Optional: for extra moist buns, drizzle about 1/4 cup of heavy cream over the buns before you bake them.
Preheat oven to 350 deg F and bake for about 20 min until golden brown.