Directions

1. HEAT oven to 350°F. Spray 13 x 9-inch baking pan with no-stick cooking spray. Combine brown sugar, 1 1/4 cups peanut butter and 1/2 cup butter in medium bowl; mix until smooth. Add eggs; beat until well mixed.
2. COMBINE flour, baking powder and salt; stir into peanut butter mixture. Add peanut butter or chocolate chips, if desired. Stir until well mixed. Pour into prepared pan.
3. BAKE 25 to 30 minutes or until brownies begin to pull away from sides. Cool on wire rack.
4. COMBINE remaining peanut butter, remaining butter, powdered sugar, vanilla and three tablespoons milk. Beat until smooth.
5. STIR in milk until frosting is spreading consistency. Spread over brownies.