OVEN 350F In large mixing bowl combine 2 1/2 cups of the flour and the yeast. Heat milk, 1/2 cup sugar, shortening, and 1 teaspoon salt just till warm (115-120F), stirring constantly till shortening almost melts. Add to dry mixture; add eggs.
Beat at low speed of electric mixer for 1/2 minute, scraping bowl. Beat 3 minutes at high speed. By hand, stir in enough remaining flour to make a soft dough. Knead on a lightly floured surface till smooth and elastic, 8 to 10 minutes. Shape in ball. Place in greased bowl; turn once. Cover; let rise in warm place till double, 1 to 1 1/4 hours.
Grease a 10-inch tube pan. Shape dough into 28 balls. Roll each in melted butter, then in mixture of 3/4 cup sugar and cinnamon. Arrange in pan; sprinkle with any remaining sugar mixture. If nuts are used, scatter among the balls as pan is filled. Let rise till double, about 1 hour.
Bake at 350F for 35 to 40 minutes. Cool in pan 15 to 20 minutes. Invert on rack; remove pan.