Heat oven to 350°F (325°F for dark or nonstick pan).

Spray bottom and sides of 9-inch square pan with baking spray with flour.

Make brownie batter as directed on box.

Spread half of batter in pan.

Bake 18 minutes.

Meanwhile, in large microwavable bowl, microwave caramels and whipping cream uncovered on High 2 to 3 minutes, stirring occasionally, until smooth.

Pour caramel over partially baked brownies; spread to within ¼ inch of edges.

Sprinkle with ⅔ cup of the chocolate chunks and ⅓ cup of the pecans.

Drop remaining brownie batter by small spoonfuls onto caramel layer.

Sprinkle with remaining ⅔ cup chocolate chunks and ⅓ cup pecans.

Bake 34 to 37 minutes longer or until center is almost set.

Cool 1 hour at room temperature.

Cover; refrigerate 1 hour before serving.

Cut into 6 rows by 4 rows.

Store covered at room temperature.