1. Make the Pretzel Crust:
- Preheat oven to 350°F (175°C).
- In a bowl, combine the crushed pretzels, melted butter, and sugar.
- Press the mixture into the bottom of an ungreased 13×9-inch baking dish.
- Bake for 10 minutes.
- Cool on a wire rack.
2. Make the Cream Cheese Filling:
- In a small bowl, beat the whipped topping, softened cream cheese, and sugar until smooth.
- Spread the filling evenly over the cooled pretzel crust.
- Refrigerate until chilled.
3. Make the Strawberry-Gelatin Topping:
- In a large bowl, dissolve the strawberry gelatin in the boiling water.
- Stir in the thawed, sweetened sliced strawberries.
- Refrigerate until partially set (this will be a slightly thickened, syrupy consistency).
4. Assemble the Salad:
- Carefully spoon the partially set strawberry-gelatin mixture over the chilled cream cheese filling.
5. Chill:
- Refrigerate until firm, 4-6 hours, or preferably overnight.
6. Serve:
- Cut into squares.
- Serve with additional whipped topping and pretzels, if desired.