In a large bowl, combine the pretzels, butter and sugar. Press into an ungreased 13-in. x 9-in. baking dish. Bake at 350° for 10 minutes. Cool completely.
In a large bowl, beat cream cheese and sugar until smooth. Stir in whipped topping. Spread over pretzel crust. Cover and refrigerate until chilled.
For topping, in a small bowl, dissolve gelatin in boiling water. Add cold water; chill until partially set. Carefully pour over filling. Cover and refrigerate for 4-6 hours or until firm. Cut into squares. Yield: 12-16 servings.