Broil chile peppers on an aluminum foil-lined baking sheet 5 inches from heat for 5 minutes on each side or until peppers look blistered.
Place peppers in a large zip-top plastic bag; seal and let stand 10 minutes to loosen skins. Peel peppers. Carefully cut peppers open lengthwise on one side, keeping stems intact; discard seeds. Set peppers aside.
Process egg whites in a food processor until foamy. Add mozzarella cheese and next 5 ingredients, processing until blended.
Place cheese mixture in a large bowl. Stir in crabmeat and next 3 ingredients.
Spoon crabmeat mixture evenly into peppers, pinching cut edges together to seal. Arrange stuffed peppers, seam side down, in a 13 x 9 inch baking dish coated with cooking spray.
Bake, covered at 375 degrees F. for 25-30 minutes or until thoroughly heated. Top with Mango Salsa, and garnish with cilantro if desired.