Preheat oven to 350°F. Line an 8x8 baking dish with parchment paper with edges overhanging for easy bar removal.
In the bowl of a stand mixer or a large mixing bowl, combine the dry cake mix, butter and egg until well blended. Note: It will not be a batter. It will be a crumble. Press crumble mixture into the prepared parchment lined baking dish.
In the same mixing bowl, mix together the cream cheese, strawberry jello mix, powdered sugar and egg. Mix until creamy and no lumps appear. Spread evenly over the bottom layer.
Bake at 350° degrees for 30 minutes or until a toothpick inserted in the center comes out clean. Cool for at least 15 minutes. Remove bars by pulling up the parchment paper with the bars on them, and lay flat on a surface. Cut into small squares and dust with powdered sugar if desired.
Bars can be made ahead and once cooled, stored in the refrigerator until ready to cut and serve.