Preheat oven to 375° F. Lightly spray a 13 x 9-inch baking pan with nonstick cooking spray.
Spread raspberries evenly over bottom of pan.
Prepare cake according to package directions and pour batter over raspberries.
Heat 2 cups water until boiling and in mixing bowl, mix water, raspberry gelatin and cornstarch together. Pour gelatin mixture over cake batter. Bake 40 to 45 minutes or until a wooden pick inserted in center comes out clean.
Chop chocolate into small pieces and sprinkle over cake. Dust with confectioners' sugar.
Servings: