Preheat oven to 350°. In a large bowl, combine cake mix, 1/4 cup egg substitute and oil; mix until blended. Reserve 1/2 cup mixture for topping. Press remaining mixture onto bottom of a 13x9-in. baking pan coated with cooking spray. Bake 11-13 minutes or until edges are light brown.
In a small bowl, beat cream cheese, sugar and lemon juice until smooth. Add remaining egg substitute; beat on low speed just until blended. Spread over crust. Crumble reserved topping over filling.
Bake 11-13 minutes longer or until filling is set. Cool on a wire rack 1 hour. Cut into bars. Refrigerate leftovers.