Mix flour, butter, pecans and brown sugar. Press on to a pizza pan. Bake for 15 minutes at 400 degrees F.
Mix powdered sugar and cream cheese. Put cream cheese in bowl first, then add powered sugar a little at a time. Fold in Cool Whip. Spread on cooled crust.
Mix Jell-O and 1/2 cup juice or water. Dissolve cornstarch in the other 1/2 cup juice. Stir into Jell-O mixture and cook until thick. Stir in sliced strawberries. Allow to cool. Pour over cream cheese mixture and refrigerate until cool.