Start by preheating your oven to 350°F (175°C). This ensures your blondies bake evenly and turn out perfectly gooey.
Line a 9x13 inch baking pan with parchment paper, leaving some overhang on the sides. This will make it easier to lift the blondies out once they’re baked.
In a large mixing bowl, combine the softened unsalted butter and packed brown sugar. Use a whisk or an electric mixer to cream them together until the mixture is smooth and light in color.
Beat in the eggs, one at a time, ensuring each is fully incorporated before adding the next. Then, mix in the tablespoon of vanilla extract until combined.
In another bowl, whisk together the salt, baking powder, and all-purpose flour. Gradually add this dry mixture to the wet ingredients, stirring until just combined. Be careful not to overmix!
Gently fold in your choice of mix-ins. This is where you can get creative! Whether you choose chocolate chips, nuts, or chopped candy bars, make sure they are evenly distributed throughout the batter.
Pour the batter into the prepared baking pan and spread it out evenly. Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted into the center comes out with a few moist crumbs.
Once baked, remove the blondies from the oven and let them cool in the pan for about 10 minutes. Then, use the parchment paper to lift them out and place them on a wire rack to cool completely. Cut into squares and enjoy!
