1For the Salted Caramel Sauce, place sugar and butter in medium saucepan on medium heat. Cook and stir with wire whisk 6 to 7 minutes or until mixture turns a deep amber color. Carefully stir in cream, vanilla and sea salt. (Mixture will be bubbly.) Whisking constantly, cook 1 to 2 minutes until sauce thickens and coats back of spoon.
2Preheat oven to 325°F. For the Chocolate Chunk Bars, mix flour, baking soda and salt in medium bowl. Set aside. Mix butter and sugars in large bowl until well blended. Add eggs and vanilla; mix well. Add flour mixture; mix just until moistened. Stir in chopped chocolate. Spread 1/2 of the batter in foil-lined 13x9-inch baking sprayed with no stick cooking spray. Pour Salted Caramel Sauce over batter, spreading to within 1/2 inch of edges. Spread remaining batter over caramel.
3Bake 35 to 40 minutes or until top is golden brown. Cool in pan on wire rack. Use foil handles to remove dessert from pan. Place on cutting board and cut into bars.