Start by sprinkling yeast over the 1/2 cup lukewarm water.
In heavy-duty mixer with dough hook on medium speed, cream together the 1 cup butter and 2/3 cup sugar until sugar is dissolved and the mixture is light and fluffy.
Beat in the yeast mixture, milk, salt, 1/12 teaspoons vanilla, eggs, and 5 1/2 cups of the flour.
Beat for a couple of minutes, adding additional flour 1/4 cup at a time.
When dough is thick enough to start pulling together in a ball, reduce speed appropriate for kneading.
Add no more flour than necessary for it not to be sticky.
Knead for about 15 minutes.
(I think this extended kneading help makes dough light and soft).
Transfer to an oiled bowl and turn to coat with oil.
Cover and let rise in a warm, draft-free spot, until dough doubles (1 to 1 1/2 hours).
While dough is rising, prepare filling: Stir together 1 cup granulated sugar, 1/2 cup brown sugar, and 3 tablespoons cinnamon in small bowl.
Line two 15 x 10-inch cookie sheets with parchment and brush with melted butter.
Roll dough until it is 12 x 18-inch rectangle.
Brush with remaining butter (but leave about 1/2 inch at long side[on other side from you] with no butter so it will stick when rolled up).
Sprinkle with sugar/cinnamon filling mixture.
Roll up dough from longer side[close to you], snug but not too tight.
Cut dough with sharp knife (or dental floss--if you know that trick--crossing it around roll and pulling quickly) in slices approxamitely 1" thick.
Arrange in pan and cover loosely with foil (coated with non-stick spray so it won't stick). (DON'T BE TEMPTED TO CROWD THEM IN THE PAN -- they will end up doughy--not cooked all the way through. They rise and spread.).
(I also brush a bit of butter between sides of rolls so that when they rise they won't stick completely to each other--helps separate them when you serve them).
To prepare glaze, mix ingredients with 2 tablespoons warm water.
If it is too thick, add additionly warm water until it is thin enough to drop easily from a spoon.
WANT TO EAT THEM IN ABOUT AN HOUR AND A HALF?.
Let dough rise until doubled again, about 45 minutes to an hour.
Preheat oven to 350°F.
Bake rolls for 20 to 25 minutes, until puffy and golden brown.
Let cool 5 minutes or so and then drizzle glaze over warm rolls and serve.
FOR OVERNIGHT RISING, after rolls are shaped and arranged on pan, cover and place in the refrigerator to rise overnight (8 to 10 hours).
Take them out to sit at room temperature for about 20 minutes before baking.
There is plenty of cinnamon sugar--I don't use all of it. Use according to your own tastes. ?