Preheat oven to 350 degrees. Spray a 9x9 inch square baking pan with nonstick spray, line with parchment paper leaving an overhang of 1-inch on the sides, then spray parchment paper.
Prepare fudge brownie batter according to package instructions and bake for 15 minutes. In a medium saucepan, melt butter and brown sugar over medium heat until sugar dissolves. Remove from heat and stir in corn syrup, eggs, vanilla extract, pecans and a pinch of salt. Spoon pecans over brownies in an even layer, then bake until topping is just set, about 30-35 minutes.
Let cool to room temperature, then cut into squares to serve.