In a small bowl combine chili powder, cumin, and salt. Cut each turkey tenderloin in half horizontally to form two 1/2-inch steaks. Use your fingers to rub the cumin mixture evenly onto both sides of turkey. Place turkey on the unheated rack of a broiler pan. Broil 4 to 5 inches from the heat for 8 to 10 minutes or until turkey is done (170 degree F), turning once. Cut turkey into thin bite-size strips.
For filling, in a medium bowl combine the cheddar cheese and sour cream dip. Stir in turkey strips. Set aside.
Meanwhile, stack tortillas and wrap in microwave-safe paper towels. Microwave on 100 percent power (high) for 10 to 15 seconds or until heated through. (Or, stack tortillas and wrap in foil; bake in a 450 degree F oven about 5 minutes.)
To assemble each chimichanga, place filling on a warm tortilla just below center. Fold bottom edge up and over filling just until mixture is covered. Fold in the sides; roll up tortilla. Secure with wooden toothpicks. Coat both sides of chimichangas with cooking spray. Place on a baking sheet.
Bake in a 450 degree F oven for 7 to 10 minutes or until tortillas are brown and crisp. To serve, top the chimichangas with salsa and, if desired, sprinkle with cilantro. Makes 2 servings.