Preheat your oven to 350 degrees Fahrenheit, ensuring it’s fully heated before the brownies go in.
Grease a 9×13 inch baking dish with a bit of butter or cooking spray.
In a large mixing bowl, combine the melted butter and brown sugar until well mixed.
Add the vanilla extract and eggs, stirring until smooth.
In a separate bowl, whisk together the flour, baking powder, baking soda, and salt.
Gradually add these dry ingredients to the wet mixture, stirring until just combined.
Fold in the white chocolate chips and chopped pecans until evenly distributed throughout the batter.
Pour the batter into your prepared baking dish, spreading it evenly.
Bake in your preheated oven for approximately 20 to 25 minutes, or until a toothpick inserted in the center comes out clean.
Let the blondies cool before cutting into squares.