Combine Jell-O with boiling water in mixing bowl. Whisk until Jell-O is dissolved. Let cool until soft set.
Preheat oven to 350 degrees F.
Next prepare the pretzel crust by mixing together crushed pretzels, melted butter, and sugar in a mixing bowl until combined. Press into a 9'' x 13'' pan.
Bake crust in preheated oven for 10 minutes. Let cool.
In a mixing bowl beat cream cheese with sugar until smooth. Fold in Cool Whip. Spread over cooled pretzel crust. Make sure to get it all the way over to the edge to prevent the strawberry layer from running into the other layers. Refrigerate 30 minutes.
Place sliced strawberries on top of cream cheese layer. SLOWLY pour Jell-O mixture over strawberries. Refrigerate until set.
Store leftovers in refrigerator.
You can substitute 10 oz frozen strawberries for the fresh strawberries.