Pre-heat oven to 400 degrees. In a small mixing bowl combine crushed pretzels, melted butter and sugar. Mix until pretzels are well-coated. Press mixture into a 9 x 13 baking dish and bake for 5 minutes. Let cool completely.
With an electric mixture, beat to whipping cream until firm peaks form. Set aside. In a separate bowl, beat the cream cheese, sugar, and pineapple together. Fold the whipped cream into the mixture.
Spread the cream cheese mixture over the pretzel crust. Make sure you completely seal the crust with this layer. Otherwise, the Jell-O layer will seep through and make the pretzel crust become soggy. Chill this layer in the freezer while preparing the Jell-O layer.
Set the Jell-O with 2 Cups of boiling water, stirring until the sugars are totally dissolved. Mix the frozen strawberries into the Jell-O and let set until the mixture becomes syrupy. Slowly pour this mixture over the cream cheese layer.
Set the Jell-O overnight. Cut into squares and use a metal spatula to serve.