Small Batch Blondies

Ingredients

• 3 tablespoons unsalted butter, melted
• 1/2 cup brown sugar
• 1 large egg yolk
• 1/2 teaspoon vanilla
• 1/4 teaspoon fine sea salt
• 1/2 cup flour
• 1/4 teaspoon baking powder
• Optional: 1/4 cup chocolate chips, raisins or nuts

Directions

1. Preheat the oven to 350°F and ensure a rack is in the middle position of the oven.
2. Line a loaf pan with enough parchment paper to overhang the sides and make handles for lifting the blondies out.
3. In a medium bowl, stir together melted butter and brown sugar until well blended. 
4. Add the vanilla and salt, and stir to combine.
5. Next, add in the egg yolk; stir to combine.
6. Sprinkle the flour and baking powder evenly on top and fold it together. Do 50 brisk strokes with a wooden spoon to incorporate the flour and activate the gluten.
7. Finally, stir in any additions, like chocolate chips and nuts (if using).
8. Bake for 17-19 minutes. Use a toothpick to test for doneness—you don’t want the toothpick to come out dry; some moist crumbs clinging is what you’re looking for.
9. Let the blondies cool in the pan, and then slice into 4 pieces (or 8 small pieces) and serve.

Notes
You can use light or dark brown sugar with this recipe.  Please refrain from adding the entire egg--your blondies will be cakey instead of chewy and gooey.

Source
https://www.dessertfortwo.com/perfect-blondies/