Crust: Preheat oven to 350 degrees. Place pretzels in a 1 gallon size re-sealable bag and crush with a rolling pin. Add melted butter and sugar to the bag, re-seal and mix well. Pat mixture into a 9x13-inch baking dish and bake for 10 minutes. Let cool before adding the other layers.
Filling: In a large bowl, beat cream cheese and confectioners' sugar, until smooth. Gently fold in Cool Whip until well combined. Spread evenly over top of cooled crust.
Topping: In a saucepan, bring water to a boil, remove from heat and whisk in Jell-O until dissolved. Set aside to cool slightly (about 10-15 minutes) then quickly stir in frozen raspberries, immediately pour over top of cream cheese filling, spread evenly. Place in the refrigerator and allow Jell-O to set up completely.