1. Activate Yeast: In a large bowl, dissolve yeast in warm water with ½ cup of sugar. Let stand for 5-10 minutes until foamy.
2. Make Dough: Add oil, salt, eggs, 4 cups of flour, and 2 teaspoons of cinnamon to the yeast mixture. Mix until combined. Stir in raisins and gradually add remaining flour until a soft dough forms. Knead for 6-8 minutes until smooth and tacky.
3. First Rise: Place dough in a greased bowl, cover, and let rise in a warm place for 1 hour, or until doubled in size. Punch down dough.
4. Shape Loaves: Divide dough in half. Roll each half into a 15×9 inch rectangle. Brush with softened butter. Combine remaining sugar and 1 tablespoon of cinnamon. Sprinkle over the dough, leaving a ½-inch border. Roll up tightly, starting with the short side. Pinch seams to seal. Place in two greased 9×5 inch loaf pans.
5. Second Rise: Cover and let rise until doubled, about 30 minutes.
6. Bake: Preheat oven to 375°F (190°C). Bake loaves for 30 minutes, or until golden brown and cooked through.
7. Cool: Remove from pans and let cool completely on a wire rack.

Make Frosting:

1. Cream Shortening and Butter: Beat together shortening and butter until fluffy.
2. Add Remaining Ingredients: Gradually add powdered sugar, beating until combined. Add vanilla extract and milk, 1 tablespoon at a time, until desired consistency is reached.

Frost and Serve:

1. Frost Loaves: Once the bread has cooled completely, frost with the prepared frosting.