1Heat oven to 350°F. In medium bowl, mix crushed pretzels, sugar and butter. Press in ungreased 13x9-inch pan. Bake 8 minutes. Cool 20 minutes.
2In medium bowl, stir brownie mix, contents of chocolate syrup pouch (from brownie mix box), water, oil and eggs until blended. Carefully spread batter over cooled crust.
3Bake 19 to 22 minutes or until toothpick comes out almost clean. Cool completely on cooling rack, about 1 hour.
4Frost cooled brownies with vanilla frosting. Sprinkle with chopped pretzels and nuts. Cut into 4 rows by 6 rows.