Preheat your oven to 350°F (175°C). In a food processor, pulse the crushed pretzels with brown sugar until well combined. Then, mix in the melted salted butter until everything is evenly coated. Press this mixture firmly into the bottom of an 8x8-inch baking dish. Bake for 10 minutes or until lightly golden, then let it cool completely before adding the next layer.

In a large mixing bowl, beat the room-temperature cream cheese, powdered sugar, and vanilla extract together until smooth and creamy for about 3-5 minutes. Gradually add the heavy cream and continue to whip until the mixture becomes fluffy and holds soft peaks. Spread this cream cheese filling over the cooled pretzel crust and refrigerate for about 1 hour to set.

While the cream cheese layer is chilling, dissolve the strawberry-flavored gelatin powder in 1 cup of boiling water, stirring until fully dissolved. Allow the mixture to cool until it thickens slightly, about 15-20 minutes. Gently fold in the sliced strawberries, ensuring they're evenly coated.

Carefully pour the strawberry gelatin mixture over the chilled cream cheese layer, spreading it evenly. Transfer the assembled Strawberry Pretzel Salad to the refrigerator and chill for 2-4 hours, or until the gelatin is completely set and firm.

When ready to serve, remove the salad from the refrigerator. Using a sharp knife, slice it into squares for clean edges. Serve each piece chilled.