Preheat oven to 350°. Line bottom and sides of an 8-inch pan with aluminum foil, allowing 2 to 3 inches to extend over sides; lightly grease foil.
Microwave chocolate squares and butter in a large microwave-safe bowl at HIGH 1 1/2 to 2 minutes or until melted and smooth, stirring at 30-second intervals. Whisk in granulated and brown sugars. Add eggs, 1 at a time, whisking just until blended after each addition. Whisk in flour, vanilla, and salt.
Pour mixture into prepared pan; sprinkle pretzel sticks and chopped nougat bars over batter.
Bake at 350° for 52 to 54 minutes or until a wooden pick inserted in center comes out with a few moist crumbs. Cool completely on a wire rack (about 1 hour). Lift brownies from pan, using foil sides as handles. Gently remove foil, and cut brownies into 16 squares.
Note: Be sure to insert wooden pick into brownies, not candy bar pieces, when testing for doneness. We tested with Snickers King Size candy bars.