Prepare gelatin according to package directions and chill until slightly thickened but not set. Beat with electric beater until thick and fluffy. Whip 1 cup cream and fold into gelatin, then fold in jam. Rinse a 2-quart mold in cold water and pour mixture into it; chill until firm. Whip remaining 1 cup cream, unmold dessert, and top with the whipped cream and raspberries.