Preheat the oven to 400°F (200°C). In a medium bowl, combine the crushed pretzels, melted butter, and 3 tablespoons of sugar. Stir until fully incorporated. Press the mixture evenly into the bottom of a 9x13-inch baking dish. Bake for 8–10 minutes or until lightly set. Remove from the oven and allow the crust to cool completely.

In a large mixing bowl, beat the softened cream cheese and 1 cup of granulated sugar with an electric mixer until the mixture is smooth and fluffy. Gently fold in the thawed whipped topping until well blended. Spread this cream mixture evenly over the cooled pretzel crust, ensuring it reaches the edges to create a seal. This helps prevent the gelatin layer from seeping into the crust.

In a separate bowl, dissolve the strawberry gelatin powder in 2 cups of boiling water. Stir until completely dissolved. Add the frozen strawberries directly into the hot gelatin and stir until the mixture thickens slightly. Allow the mixture to sit for a few minutes to cool slightly before pouring.

Carefully pour the gelatin and strawberry mixture over the cream cheese layer. Spread evenly to cover. Refrigerate the assembled dish for at least 2 hours, or until fully set.

Once the salad is firm, slice into squares and serve chilled. Store any leftovers in the refrigerator, covered, for up to 3–4 days.