In large mixer bowl combine 3 1/2 cups of the flour and the yeast.
In saucepan heat milk, 1/2 cup sugar, shortening, and salt just till warm (115-120°), stirring constantly to melt shortening. Add to dry mixture in mixer bowl; add eggs. Beat at low speed with electric mixer for 1/2 minute, scraping sides of bowl constantly. Beat 3 minutes at high speed.
By hand, stir in enough of the remaining flour to make a moderately soft dough. Turn out on lightly floured surface and knead till smooth and elastic (5 to 8 minutes). Shape into a ball. Place in lightly greased bowl, turning once to grease surface.
Cover; let rise in warm place till double (about 1 hour). Punch dough down; turn out on lightly floured surface. Divide in half. Cover, let rest 10 minutes. Roll each half into a 15 x 7-inch rectangle. Brush entire surface with water.
Combine the 1/2 cup sugar and the ground cinnamon. Spread each rectangle with half the sugar-cinnamon mixture. Roll dough up as for jelly-roll, beginning with narrow side. Seal long edge and ends. Place, sealed edge down, in 2 greased 9x5x3-inch loaf pans. Cover and let rise in warm place till almost double (35 to 45 minutes).
Bake at 375° till done, 35-45 minutes. (If crust browns too quickly, cover with foil last 15 minutes of baking.) Remove bread from pans and cool on wire racks.