Preheat oven to 350°F (175°C). Grease a 9"x 13"x 2" baking pan.
Whisk together the flour, baking powder, and salt. Set aside.
In a separate bowl, combine the butter, brown sugar, eggs, and vanilla until thoroughly mixed. Stir in the flour mixture, mixing just until combined. Stir in the chocolate chips and pecans.
Transfer the batter to the prepared pan, and spread evenly. Bake 30 to 35 minutes, or until a pick inserted into the center comes out clean. Set the pan on a wire rack to cool.
To make the ganache:
Place the chocolate and corn syrup in a heatproof bowl. Set aside.
Place the cream in a heavy saucepan. Bring to a boil over medium-high heat. Remove the cream from the heat, and pour it over the chocolate. Let sit for 5 minutes. Then stir until smooth.
Pour the ganache over the blondies. Garnish with chopped pecans. Allow the ganache to set (10-15 minutes) before cutting into bars.
Notes
*The corn syrup is not necessary, per se. I sometimes like to add just that little bit of it to make the ganache hold up a little better. If you prefer not to use corn syrup, that's absolutely fine.