Spray a 4-cup gelatin mold or a 9-inch square pan with vegetable oil cooking spray. In a medium glass mixing bowl, combine the raspberry gelatin and unflavored gelatin. Add 1 cup boiling water and stir with a metal spoon continuously for 2 minutes, until the gelatin is completely dissolved. Stir in 1/2 cup cold water. Add the pineapple and juice, cranberry sauce, and walnuts. Stir with a metal spoon until all ingredients are completely incorporated. Pour the mixture into the prepared mold, cover with plastic wrap and refrigerate until firm.