Prepare the Oven and Pan: Begin by preheating your oven to 350°F (175°C). Grease a 9x13 inch baking pan thoroughly with non-stick spray, or line it with parchment paper for easy removal after baking.
Mix the Sugars and Butter: In a large mixing bowl, pour in the melted butter, then add the packed brown sugar and granulated sugar. Using a whisk or a hand mixer, blend the mixture until it is smooth and well combined.
Incorporate the Eggs and Vanilla: Crack the eggs into the sugar and butter mixture one at a time. Beat well after each addition to ensure they’re fully incorporated. Next, stir in the vanilla extract, mixing until everything is evenly combined.
Combine Dry Ingredients: In a separate bowl, whisk together the all-purpose flour, baking powder, fine sea salt, and ground cinnamon. This helps to evenly distribute the baking powder and spices throughout the flour.
Combine Wet and Dry Mixtures: Gradually add the dry ingredients to the wet mixture, stirring gently until just combined. Do not overmix to maintain a tender texture. If you choose to include white chocolate chips, fold them in gently at this stage.
Spread the Batter: Pour the blondie batter into the prepared baking pan. Use a spatula to spread it evenly across the pan for uniform baking.
Bake the Blondies: Place the pan in the preheated oven and bake for 20 to 25 minutes. The blondies are done when a toothpick inserted into the center comes out with a few moist crumbs clinging to it, not wet batter.
Cool Down: Allow the blondies to cool in the pan for at least 10 minutes. Afterward, transfer them to a wire rack to cool completely, which will help them become firmer for cutting.
Notes
For a delightful finishing touch, sprinkle a light dusting of cinnamon sugar over the tops before serving.