HEAT oven to 350ºF.
LINE 13x9-inch pan with foil, with ends of foil extending over sides. Microwave butter in large microwaveable bowl on HIGH 1 to 1-1/2 min. or until melted. Add dry cake mix, 1 egg and 1 Tbsp. lemon juice; beat with mixer until blended. Press 2/3 of the dough onto bottom of prepared pan.
BEAT cream cheese and sugar with mixer until blended. Add remaining egg, lemon juice and zest; mix well. Pour over crust; top with berries. Pinch small pieces of the remaining dough between your fingers; press lightly into cream cheese layer.
BAKE 48 to 50 min. or until centre is almost set. Cool completely. Refrigerate 1 hour. Use foil handles to lift dessert from pan before cutting into bars.