¾cup(170 g or 12 Tbs) unsalted butter, melted and slightly cooled
1 ½cups(300 g) packed light or dark brown sugar
2large eggs, room temperature
2teaspoonspure vanilla extract
½cup(80 g) semisweet chocolate chips
½cup(80 g) white chocolate chips
1cupchopped pecans, (or walnuts)
Instructions
Preheat oven to 350° F. Line a 13-inch by 9-inch baking pan with parchment paper. Set aside.
In a medium bowl, whisk together flour, baking powder and salt. Set aside.
In a large bowl, whisk together melted butter and brown sugar. Stir vigorously for about 1 minute until the sugar absorbs the butter. Add eggs and vanilla. Mix until combined.
Stir in flour mixture with a wooden spoon or spatula. Mix just until combined. It's okay if there are a couple pockets of flour. That will disappear when you add the chocolate and nuts.
Stir in semisweet chocolate chips, white chocolate chips and chopped pecans. Transfer batter to prepared baking pan. The batter will be thick, but can be spread with an offset spatula.
Bake bars for 22 to 24 minutes or until the top is golden and shiny. Place pan on a wire rack to cool completely. Cut bars into four rows by 6 columns to yield 24 bars.
Notes
Storing blondies: Store blondies in an airtight container at room temperature for up to 5 days.Freezing blondies: Once cooled, wrap blondies (uncut) in plastic wrap and aluminum foil. Freeze on a flat surface for up to one month. Defrost in the refrigerator before cutting and serving at room temperature.High altitude adjustments: Decrease brown sugar by 2 Tablespoons. Decrease baking powder by 1/4 teaspoon.Suggested tools:
Kitchen scale: It's much more accurate to weigh your ingredients instead of measuring them by the cup.