Position a rack in the center of the oven. Preheat oven to 350°. Spray an 8x8 pan, although I have used a 9 x 13 because I did not plan accordingly and it gave me a flatter blondie that could be cut into a bar. If you use a bigger pan the product will cook a lot faster. The book suggest using aluminum foil to lift the product off the pan after it has cooled. I prefer the cooking spray.
Toast pecans In a heavy saute pan, stirring continuously, until light brown for about 5 to 8 minutes. Set aside.
Whip together; all-purpose flour, baking powder, baking soda, salt. Set aside.
In a large, heavy saucepan, melt the butter. Then boil it, stirring constantly, until golden brown, for about 4 minutes. *Once butter turns color it continues to turn rather fast. Please do not leave the butter unattended and pull it off the heat sooner than later, as it will continue to turn off the heat.
Remove from heat and add both sugars until well blended. Let cool to barely warm.
Stir until well combined; egg, egg yolk, maple syrup, and vanilla
Stir in flour mixture and pecans. Scrape batter into baking pan and spread to the edges.
bake until golden brown and a toothpick or a fork inserted comes out clean, 28 to 33 minutes.
Remove pan from and let it cool.
Cut blondies.