Place salmon in an ungreased 8-in. square baking dish. Bake, uncovered, at 350° for 20-25 minutes or until fish flakes easily with a fork.
In a small saucepan, combine the cornstarch, pineapple juice, soy sauce and water until smooth. Stir in the brown sugar, ginger and cayenne. Bring to a boil; cook and stir for 1-2 minutes or until thickened. Add pineapple; heat through. Serve with salmon.