1Heat oven to 350°F (325°F for dark or nonstick pan). In large bowl, beat dry cake mix, butter and 1 of the eggs with electric mixer on low speed until crumbly. Press in bottom of ungreased 13x9-inch pan.
2In medium bowl, beat cream cheese with electric mixer on medium speed until smooth. Gradually beat in powdered sugar on low speed. Stir in lemon peel and lemon juice until smooth. Reserve 1/2 cup; refrigerate. Beat remaining 2 eggs into remaining cream cheese mixture on medium speed until blended. Spread over cake mixture.
3Bake bars 23 to 28 minutes or until set. Cool completely, about 1 hour. Spread with reserved cream cheese mixture. Refrigerate about 3 hours or until firm. For bars, cut into 8 rows by 6 rows. Store covered in refrigerator.