Preheat oven to 350°. In a small bowl, combine pretzels, butter and sugar; spread onto a baking sheet. Bake until crisp and lightly browned, 12-15 minutes. Cool completely on a wire rack; break into small pieces.
For filling, in a small bowl, beat whipped topping, cream cheese and sugar until smooth. Refrigerate until chilled.
For topping, in a large bowl, dissolve gelatin in boiling water. Stir in sweetened strawberries; chill until partially set, about 1 hour. Carefully layer pretzel mixture, filling and topping into 4-oz. glass jars. Chill until firm, at least 2 hours. If desired, serve with additional whipped topping and pretzels.