Pre-heat the oven to 350 and spray a 13 x 9" or similar sized pan with cooking spray
Meanwhile, crush the pretzels into small pieces. I put them in a baggie and whacked them with a rolling pin.
Mix the pretzels, sugar and butter in the pan and bake for 10 - 12 minutes to form the crust. Allow to cool before adding the cream cheese layer.
Whip the heavy cream in one bowl and set aside while you beat the cream cheese with the sugar. Fold in the whipped cream.
When the pretzel layer is cool to the touch, spread the cream cheese layer over top, going all the way to the edges.
Place in the fridge until ready to add the jello layer.
Combine 2 cups boiling water with the JELL-O as directed on the package.
Stir in the frozen strawberries and continue to stir until the jello begins to set.
Place in the fridge and check after 20 minutes. When the jello is mostly set, but still pourable, pour over the cream cheese layer and spread. Use a spoon to redistribute the strawberries evenly as necessary.
Return the pan to the fridge for another 2 hours or so or until the jello is completely set.
Serve with more whipped cream as desired.