How to Make It
Place carrots in a 5-quart slow cooker. Arrange turkey over carrots. Stir together dark brown sugar, apple butter, juice concentrate, pumpkin pie spice, salt, dry mustard, and crushed red pepper. Pour mixture over turkey tenderloins, and top with rosemary sprigs. Cover and cook on HIGH 1 hour. Reduce heat to LOW, and cook until turkey and carrots are tender, about 5 hours. Place turkey and carrots on a serving platter.
Pour juices from slow cooker through a wire-mesh strainer into a 3-quart saucepan, discarding solids. Bring to a boil over high. Whisk together cornstarch and water in a small bowl until smooth. Gradually whisk cornstarch mixture into juices, and cook, whisking constantly, until thickened, about 1 minute. Serve sauce over turkey and carrots. Garnish with orange zest.