Preheat oven to 350 degrees.
Combine crushed pretzels, softened butter and 3 Tbs of sugar. Mix well.
Press in the bottom of a 9" x 13" pan and bake at 350 deg for 10 minutes.
While the crust is baking and cooling, cream the softened cream cheese and 1 cup of sugar in a medium mixing bowl.
Gently fold in the 8 oz. whipped topping, mixing well.
Spread cream mixture over the cooled pretzels.
In a large mixing bowl, dissolve the Jello into 2 cups of boiling water.
Add the frozen strawberries to the Jello, breaking them up with a fork as you stir.
Chill strawberry Jellow mixture until slightly thickened.
Pour over the Cool Whip layer.
Refrigerate for 4 hours, until completely set.