Lemon-Blueberry Crumb Bars

1/2 c. butter
1 (2-layer) yellow cake mix
2 eggs, divided
1/2 c. sugar
2 (8 oz) pkgs. cream cheese, softened
1 Tbsp. zest and 3 Tbsp. juice from 1 lemon
2 1/2 c. fresh blueberries

Line 13-inch by 9-inch baking pan with foil with ends of foil extending over sides. Microwave butter in large bowl on high 1 to 1 1/2 minutes or until melted. Add cake mix and 1 egg; beat with mixer until well blended. Press 2/3 of mixture onto bottom of prepared pan. Beat cream cheese and sugar with mixer until well blended. Add remaining egg, zest and juice; mix well. Pour over crust; top with berries. Pinch small pieces of remaining cake mix mixture between your fingers; press lightly into cream cheese layer. Bake 55-60 minutes in preheated 350° oven or until toothpick inserted into center comes out clean. Refrigerate to cool completely. Use foil handles to lift dessert from pan before cutting into bars. Keep refrigerated.