Preheat your oven to 400°F and position the oven rack in the center. Lightly coat a 13x9 inch baking pan with cooking oil spray. Set aside 1/2 cup of pretzels for garnish.

Process the remaining pretzels with 1/4 cup of the sugar-free sweetener until coarsely ground. Combine this with the melted butter and pulse to mix.

Press the pretzel mixture into the bottom of the prepared pan and bake for 10 minutes. Allow it to cool for around 20 minutes.

In a mixing bowl, beat the cream cheese and 1/2 cup of sugar-free sweetener until light and fluffy.

Gradually add the heavy cream, mixing until soft peaks form. Spread this mixture over the cooled crust and chill for 30 minutes.

Puree 2 pounds of thawed strawberries and strain to extract the liquid.

Combine the remaining sugar-free sweetener and salt with the strawberry puree and simmer until the sweetener dissolves, about 5 minutes.

Sprinkle the gelatin over the cold water and let it bloom for 5 minutes.

Stir the warm strawberry mixture into the bloomed gelatin, add the rest of the strawberries, and chill until slightly thickened.

Pour this strawberry layer over the cream cheese layer.

Refrigerate the salad until fully set, about 4 hours or overnight, then slice and serve topped with whipped cream, a strawberry slice, and reserved pretzels.