Preheat the oven to 350°F. Line a 9x13 baking dish with parchment paper, set aside.
Melt the butter, set it aside to cool slightly as you continue with the next steps.
In a medium-sized bowl, stir together the flour, baking powder, and salt, set aside.
In a large bowl, whisk together the brown sugar, butter, eggs, and vanilla until smooth.
Add the dry ingredients to the wet and stir until combined with no dry patches.
Add the chocolate chunks and stir them in.
Spread the batter into the prepared baking dish top with some more chunks if you’d like.
Bake for 25-30 minutes until a toothpick inserted into the center comes out clean. The top will appear shiny and set.
Place on a wire rack to cool completely.
Using the parchment paper to help, lift out the blondies and cut them into bars, and serve.