In a small bowl, mix together the yeast and warm water with 1 tablespoon of the sugar.Set aside for 5 minutes until the yeast is frothy.
In a large mixing bowl, add the yeast mixture, 1/2 cup of the sugar, warmed milk, eggs,butter, salt, and 3 cups of the flour, then beat on medium speed with an electric mixer until smooth.
Stir in the remaining flour ½ cup at a time until a soft dough forms. Turn the dough out onto a lightly floured surface; knead until smooth and elastic (about 5 minutes).
Place the dough in a large greased bowl, turning once to grease the top. Cover with a clean kitchen towel and let rise in a warm place until doubled, about 1-2 hours.
In a small bowl, mix the cinnamon and remaining ½ cup of sugar together. Set aside.
Punch down the dough then turn onto a lightly floured surface.
Divide the dough in half and roll each portion into an 18×8-inch rectangle. Sprinkle each rectangle evenly with the cinnamon sugar mixture, leaving a 1/2 inch border around the edges with no cinnamon sugar. Roll up the dough jelly-roll style, forming an 8 inch long log.
Place the loaves in two greased 9×5 inch loaf pans, seam side down. Cover with kitchen towels and let rise in a warm place until doubled, about 1-1/2 hours.
Bake the loaves at 350F degrees for 30 minutes, until golden brown on top.
Remove the loaves from the pans to cool on cooling racks. Slice with a bread knife and serve with softened butter.
Makes 2 loaves; 16 servings.