Grease a 15 1/2 by10 1/2 by 1-inch jellyroll pan. Spray the pan with Pam, and line the pan with foil.
Measure the flour and salt. Melt the chocolate in the microwave, and set aside. In a large mixer bowl, cream the butter; add the vanilla, and sugars. Beat well. Add the corn syrup, and beat until smooth. Add the eggs one at a time, beating until smooth each time. Beat in the melted chocolate. On low speed, gradually add the flour. Stir in 2 cups pecans. Reserve one cup for the top.
Put the batter into the prepared pan, and spread it out to cover the whole pan. Sprinkle the top with the remaining cup of pecans. Bake for 40-45 minutes until a toothpick inserted in the center comes out clean but not dry. Cool in the pan for 30 minutes. Invert on a bread board. Remove the foil and invert on a cooling rack.
It's easier to cut these when they are quite cold. Put the cooled brownies into the freezer for 30 minutes. Cut into small bars. Yield: 32 large or 64 reasonable bars.