Spray 13x9-inch pan with cooking spray. Line with parchment, with ends of parchment extending over sides.
Microwave chocolate and butter in large microwaveable bowl on HIGH 2 min. or until butter is melted. Stir until chocolate is completely melted and mixture is well blended. Add 2 cups sugar, 3 eggs and 1 tsp. vanilla; mix well. Stir in flour. Pour into prepared pan.
Beat remaining egg in medium bowl with mixer until foamy. Add all remaining ingredients, including remaining sugar and vanilla; mix well. Drop in large spoonfuls evenly over brownie batter in pan.
Bake 20 min.; cover. Bake an additional 20 min. or until toothpick inserted in center comes out with fudgy crumbs. (Do not overbake.) Cool completely. Use parchment handles to remove brownie from pan before cutting to serve.
Calories From Fat
% Daily Value*
Total Fat 12g
Saturated Fat 5g
Trans Fat 0g
Total Carbohydrates 27g
Dietary Fibers 1g
* Percent Daily Values are based on a 2,000 calorie diet.
* Nutrition information is estimated based on the ingredients and cooking instructions as described in each recipe and is intended to be used for informational purposes only. Please note that nutrition details may vary based on methods of preparation, origin and freshness of ingredients used.