1. Preheat oven to 325°.
2. Cook bacon in a large skillet over medium heat 7 minutes or until bacon begins to brown, stirring occasionally. Stir in onion, chopped rosemary, 1/4 teaspoon salt, and 1/4 teaspoon pepper; cook for 8 minutes or until onion begins to brown, stirring occasionally. Stir in 1 cup broth, apples, and cranberries. Bring to a boil. Reduce heat, and simmer until liquid evaporates and apples are almost tender (about 15 minutes), stirring occasionally. Remove from heat, and cool slightly. Set aside 1 cup apple mixture.
3. Slice turkey tenderloins lengthwise, cutting to, but not through, the other side. Open halves, laying tenderloins flat. Place each tenderloin between 2 sheets of heavy-duty plastic wrap; pound to 1/2-inch thickness using a meat mallet or small heavy skillet. Discard plastic wrap.
4. Sprinkle remaining 3/4 teaspoon salt and 1/2 teaspoon black pepper evenly over both sides of tenderloins. Spread 1/3 cup apple mixture over each tenderloin; roll up jelly-roll fashion, starting with long sides. Secure at 2-inch intervals with twine.
5. Heat oil in a large Dutch oven over medium-high heat. Add tenderloins; cook 6 minutes, turning to brown on all sides. Add remaining 1/2 cup broth and rosemary sprigs; bring to a boil. Cover and bake at 325° for 25 minutes or until a thermometer inserted in thickest portion registers 165°. Remove tenderloins from pan; let stand 10 minutes. Slice crosswise into 1/2-inch-thick slices.
6. Strain cooking liquid through a fine mesh sieve over a bowl; discard solids. Combine flour and 1/4 cup cooking liquid, stirring with a whisk until smooth. Return flour mixture and the remaining cooking liquid to pan. Stir in reserved 1 cup apple mixture; bring to a boil. Cook for 1 minute or until thickened, stirring constantly. Serve with turkey.