Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking pan or line it with parchment paper for easy removal.
In a large mixing bowl, combine the peanut butter and softened butter. Beat with an electric mixer until the mixture is creamy and well combined.
Add the brown sugar and granulated sugar to the bowl, continuing to mix until fully integrated.
Incorporate the eggs one at a time, allowing each to mix in completely. Add the vanilla extract and mix until smooth.
In a separate bowl, whisk together the all-purpose flour, baking powder, and salt.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined. Be careful not to overmix.
Gently fold in the chocolate chips, reserving a few for sprinkling on top before baking.
Pour the batter into the prepared baking pan and spread it out evenly. Sprinkle the remaining chocolate chips on top.
Bake in the preheated oven for 25-30 minutes, or until the edges are lightly golden and a toothpick inserted in the center comes out with a few moist crumbs.
Allow to cool in the pan for about 10 minutes, then transfer to a wire rack to cool completely before cutting into squares.
Notes
Serve warm with vanilla ice cream and chocolate sauce for an indulgent treat!