Preheat your oven to 350°F (175°C) and grease an 8x8 inch baking pan, lining it with parchment paper for easy removal.

In a medium bowl, whisk together the flour, baking powder, and salt, then set this dry mixture aside.

In a large bowl, combine the melted butter, brown sugar, and granulated sugar, mixing until smooth.

Beat in the eggs one at a time, ensuring each is fully incorporated before adding the next, then stir in the vanilla extract.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined and taking care not to overmix.

Pour the batter into the prepared baking pan and spread it evenly.

Bake for 25-30 minutes, or until the edges are golden brown and a toothpick inserted into the center comes out with moist crumbs, not wet batter.

Allow the blondies to cool completely in the pan on a wire rack before cutting them into squares and serving.