Preheat your oven to 350°F. Lightly grease the bottom of a 9x13-inch baking dish with butter.
In a medium bowl, mix the crushed pretzels, ¾ cup of sugar, and melted butter until combined.
Firmly press the mixture into the bottom of the prepared pan and bake for 10 minutes.
Allow it to cool completely.
In a large mixing bowl, beat together the softened cream cheese, remaining ¾ cup of sugar, and vanilla until smooth.
Gently fold in the Cool Whip and spread the mixture evenly over the cooled pretzel crust.
In a bowl, whisk the gelatin into two cups of boiling water until fully dissolved.
Stir in the sliced strawberries, then refrigerate the mixture for about 15 minutes until it begins to thicken but is not fully set.
Pour the gelatin mixture over the cream cheese layer in the pan.
Cover and refrigerate for about 2 hours, or until the gelatin is fully set.
Slice into squares before serving.