Melt butter, mix with pretzels, sugar,and pecans. Pat into bottom of 13x9 inch pan. Bake for 8-10 minutes at 350 degrees. Cool.
Beat cream cheese,whipped topping and powdered sugar. Spread on top of pretzel mixture. Place in refrigerator for 30 minutes. Dissolve gelatin in boiling water. Add strawberries. Stir until gelatin begins to thicken. Pour over cream cheese mixture and refrigerate for about 2 hours. Cover with whipped topping if desired,