Nancy Drew blondies are like butterscotch brownies that are chewy and gooey and loaded with chocolate chips that melt into a luscious swirl. Lovely in the best, most indulgent way possible.
Position a rack in the upper third of the oven. Preheat the oven to 350°F (180°C). Line an 8-inch (20-centimeter) square baking pan with parchment paper or aluminum foil, leaving an overhang around each side.
In a medium saucepan, melt the butter over low heat. Remove the saucepan from the heat and with a wooden spoon or sturdy silicone spatula, mix in the brown sugar, vanilla, and salt until relatively smooth. Quickly stir in the egg and mix until smooth and lump-free. Add the flour, chocolate chips, and walnuts (if using) all at once. Stir the mixture until just incorporated. Spread the batter evenly in the prepared pan.
Bake for 23 to 30 minutes, until the blondies are golden and crinkly on top, set in the middle, and a toothpick or cake tester plunged into the center comes out clean or with just a few stray crumbs attached.
Let the blondies cool completely in the pan. (Hah! We know the temptation. Trust us, we know. Still, try to wait. These blondies are better after they rest a little.) Lift the ends of the parchment paper and transfer the entire block of blondies to a cutting board. Cut the block into rows of 4, 5, or 6 to yield 16, 25, or 36 squares. The blondies will keep in an airtight container at room temperature for up to 5 days. (Hah! As if you'll be able to resist for that long.)
Notes
Nancy Drew Blondies Variation
Blondies Without ChocolateIf you’re not in the mood for milk or white chocolate, you can leave it out and increase the amount of walnuts to 1 cup (105 grams). If you’re not into walnuts, either, use pecans or any kind of nut you feel to be appropriate.Bitter Chocolate BlondiesIf you prefer your blondies on the not-terribly-sweet end of the sweet spectrum, opt for dark chocolate chips and omit the white chocolate.Cakey BlondiesThe secret to the moist, chewy texture of these blondies recipe is the cold egg; if you prefer a blondie that’s a little less moist and a little more cakey, use a room-temperature egg and briefly beat it with a whisk before adding it to the batter. Once the batter is ready to be baked, add a couple more minutes oven time.