These brown butter blondies take a classic treat to the next level with rich, nutty brown butter, toffee bits, and crunchy nuts. Easy to make and full of flavor, they’re perfect for sharing or keeping all to yourself.
Place the butter in a medium saucepan, and cook over medium heat. Once the butter begins to foam, continue cooking until brown specks form beneath the foam. The foaming will dissipate and the butter will have a nutty aroma. Remove from the heat and transfer the butter to a large mixing bowl to cool until slightly warm but not hot.
Preheat oven to 350°F (175°C). Grease a 9"x 13"x 2" baking pan. Line the pan with parchment paper., and lightly grease the paper.
Whisk together the flour, baking powder, and salt. Set aside.
Add the brown sugar and granulated sugar to the cooled butter. Stir to combine.
Add the eggs. Using an electric mixer on medium speed, beat until light and fluffy. Mix in the vanilla.
Reduce mixer speed to low, and add the flour mixture in 3 portions, mixing just until combined after each addition. Stir in the cashews and toffee bits (or other add-ins).
Transfer the batter to the prepared pan, and spread evenly. Bake 35-40 minutes, or until a pick inserted into the center comes out clean. Cool the bars completely in the pan on a wire rack before removing from the pan and cutting into bars.
Notes
Measuring flour: For best results, measure by weight or use the spoon and sweep method.
Butter cooling time: Let the browned butter cool until warm but not hot before mixing.
Add-ins: Stick to a total of about 2 cups of mix-ins. Toffee bits and nuts are a great combo, but feel free to get creative!
Storage: Store in an airtight container at room temperature up to 3 days, or freeze for up to 3 months.