Heat oven to 350° (if using dark or nonstick pan, heat oven to 325°). Beat flour, brown sugar and butter in large bowl with electric mixer on medium speed, or mix with spoon. Press mixture on bottom and 1/2 inch up sides of ungreased rectangular pan, 13x9x2 inches. Bake 15 to 20 minutes or until golden brown.
Stir remaining ingredients in medium bowl until well mixed. Pour over partially baked crust.
Bake 30 to 35 minutes or until set. Cool about 15 minutes. Refrigerate at least 1 hour until firm. For bars, cut into 8 rows by 6 rows. Store covered in refrigerator.