Ingredients:
- cup (227g) unsalted butter, melted
- ½ cups (300g) light brown sugar, packed
- ½ cup (100g) granulated sugar
- large eggs, room temperature
- tablespoon vanilla extract
- ¾ cups (210g) all-purpose flour, spooned and leveled
- teaspoon baking powder
- ½ teaspoon fine sea salt
- tablespoons (56g) unsalted butter, softened (for topping)
- ¼ cup (50g) granulated sugar (for topping)
- ½ teaspoons ground cinnamon (for topping)
Instructions:
- Preheat oven to 350°F (175°C). Line an 8x8 inch metal baking pan with parchment paper, ensuring an overhang on two sides to act as handles.
- Prepare the Topping: In a small bowl, combine the 4 tablespoons softened butter, ¼ cup sugar, and 1 ½ teaspoons cinnamon until crumbly. Set this cinnamon sugar mixture aside.
- Mix Wet Ingredients: In a large bowl, whisk together the melted butter and both sugars until thoroughly combined and glossy.
- Incorporate Eggs & Vanilla: Whisk in the eggs one at a time until fully incorporated, then stir in the vanilla extract until the mixture is smooth.
- Combine Dry Ingredients: In a separate, smaller bowl, whisk together the flour, baking powder, and salt.
- Fold in Dry: Gradually add the dry mixture to the wet mixture, folding gently with a spatula until just combined. Do not overmix; a few flour streaks are acceptable.
- Assemble & Swirl: Press about two-thirds of the batter evenly into the prepared pan. Sprinkle the reserved cinnamon sugar topping evenly over the batter layer. Dollop the remaining one-third of the batter randomly over the topping. Use a knife or skewer to gently swirl the layers together just once or twice.
- Bake for 30–35 minutes. The edges should be set, but the centre should look slightly underdone. A toothpick inserted near the centre should come out with moist, fudgy crumbs attached.
- Cool Completely: Let the blondies cool completely in the pan on a wire rack (at least 2 hours is recommended) before lifting them out using the parchment handles and slicing. Cooling is vital for the chewy texture.