In a small bowl, mix together yeast with one teaspoon of the sugar and half a cup of warm milk. Set aside for about 10 minutes, until mixture is bubbly.

Sprinkle the salt into a mixer bowl and add flour, butter, eggs, remaining sugar, and remaining milk. Add the yeast mixture and knead with a dough hook until you have a soft, pliable, and slightly sticky dough. Transfer to a work surface and knead a few minutes more.

Transfer to a greased bowl, cover, and let rise until the dough doubles in volume. (You can cover with plastic wrap and allow it to rise slowly in the refrigerator, overnight.)

In a bowl, mix together the filling ingredients.

Line a baking sheet with Gefen Parchment Paper and spray lightly with cooking spray. Preheat oven to 350 degrees Fahrenheit (180 degrees Celsius).

Divide the dough in half. Roll out each piece into a quarter-inch- (half-centimeter)- thick rectangle. Spread both rectangles with the cinnamon mixture.

Roll up into a jelly-roll shape and cut into one- and-  a- quarter-inch (three-centimeter) slices, working carefully so they retain their round shape. Press down the ends of the dough of each bun and place on the prepared baking sheet, leaving three quarters of an inch (two centimeters) between the buns. Let them rise for about half an hour, or until doubled in volume.

Bake for 20 minutes, until lightly golden.

Place all frosting ingredients into a bowl and beat with a hand mixer. When the buns come out of the oven, spread with a generous amount of frosting. Serve hot.