In a medium bowl combine crushed pretzels, 3 tablespoons confectioner's (powdered) sugar and melted butter. Mix well and press into a 9 x 13 inch casserole dish.
Bake in preheated oven for 10 minutes. Cool.
To make the filling, combine in a medium bowl the cream cheese and 1 cup confectioner's (powdered) sugar; beat until smooth. Stir in whipped topping; spread mixture in crust and refrigerate.
Meanwhile, combine gelatin mix and boiling water; add strawberries. Let gelatin mixture thicken slightly, and then pour over the crust and filling layers. Refrigerate for 4 hours.