Ingredients:
- 1 stick (½ cup) Unsalted Butter, cubed
- 1 ¼ cups Light Brown Sugar, packed
- ¼ cup Granulated Sugar
- 2 Large Eggs, room temperature
- 1 tablespoon Vanilla Extract
- 1 ½ cups All-Purpose Flour, spooned and levelled
- 1 teaspoon Baking Powder
- 1 teaspoon Ground Cinnamon (for dough)
- ½ teaspoon Fine Sea Salt
- 2 tablespoons Granulated Sugar (for swirl topping)
- 1 teaspoon Ground Cinnamon (for swirl topping)
Instructions:
- Preheat the oven to 350°F (175°C). Line the 8x8 inch baking pan with parchment paper, leaving an overhang 'sling' on two sides for easy removal.
- Melt the stick of butter gently and set aside to cool slightly.
- In a medium bowl, whisk together the flour, baking powder, 1 teaspoon of ground cinnamon (for dough), and salt. Set aside.
- In a large bowl, pour the slightly cooled melted butter. Add the light brown sugar and granulated sugar. Whisk vigorously for about 1 minute until the mixture is smooth, thick, and resembles wet sand.
- Add the two large eggs one at a time, mixing well after each addition. Stir in the vanilla extract until the mixture is pale and glossy.
- Add the dry flour mixture to the wet ingredients. Use a rubber spatula to fold them together gently until just combined. Stop mixing the moment you no longer see streaks of flour.
- Scrape the blondie batter into the prepared baking pan, spreading it evenly into the corners.
- In a very small bowl, combine the 2 tablespoons of sugar and 1 teaspoon of cinnamon for the swirl topping.
- Sprinkle the cinnamon-sugar mixture evenly over the top of the batter. Use a skewer or the tip of a knife to gently swirl the mixture into the top layer of the dough.
- Bake for 30 to 35 minutes. The edges should look set and golden brown; a toothpick inserted into the center should come out with moist crumbs attached.
- Remove the pan from the oven. Allow the blondies to cool completely in the pan on a wire rack—at least 90 minutes—before lifting out using the parchment sling and slicing.