Brown Butter Blueberry Blondies

For the prep:

1. Place the butter in a medium-large microwave-safe bowl and cover the bowl tightly with a piece of plastic wrap. Take a small sharp knife and cut 3-4 slits in the top for ventilation. (You can also cover the bowl with a plate if you prefer to avoid plastic wrap.)
2. Cook the butter on high power in the microwave for 4 minutes. Open the microwave and take a peek. You’re looking for a deep golden color. You will probably need more time (my microwave is 900W and it takes 5 minutes to perfectly brown butter). Continue cooking for 30-second increments and checking until you achieve that golden brown butter. (Once you figure out the time your microwave takes, you can just set the microwave for that in the future.)
3. Remove from the microwave with a hot pad and carefully (it will be hot) remove the plastic wrap. Allow the brown butter to cool for 15 minutes while you preheat the oven, prepare the pan and get out the other ingredients.
4. Position a rack in the center of the oven and preheat to 350°F. Spray an 8-by-8-inch square baking pan with baking spray, then line the pan foil, leaving a generous overhang on two sides. Spray the foil lightly with baking spray and rub to coat with a paper towel. Set aside.

For the blondie batter:

1. Add the brown sugar to the cooled butter mixture and whisk until nice and smooth. Add the egg, vanilla and almond extract and whisk well. Sprinkle the baking powder and salt over the top and stir to combine.
2. Add the flour and stir with a sturdy silicone spatula or a wooden spoon until just combined. Stir in the white chocolate chips and ½ of the toffee bits. Gently fold in the blueberries, trying not to smush them too much.
3. Transfer the batter to the prepared pan and gently spread and smooth with an offset spatula to even the surface. Sprinkle with the remaining toffee bits.
4. Tuck extra blueberries and white chips into the top, if desired
5. Bake until the top is cracked and pale golden brown, 23–28 minutes (don’t overbake).
6. Cool in the pan for at least an hour, then (lifting the foil overhang) transfer to a cutting board and cut into squares as large or as small as you like.
7. Store in an airtight container for 12-24 hours or freeze then thaw and serve.