Preheat your oven to 350°F (175°C). Line a 9x13-inch baking pan with parchment paper, leaving some overhang on the sides for easy removal later.

In a large bowl, melt the softened unsalted butter in the microwave or on the stovetop until it’s fully liquid. I often allow the butter a moment to cool slightly before proceeding to avoid cooking the eggs.

Add the granulated white sugar and packed light brown sugar to the melted butter. Stir until fully combined. The mixture should be smooth and creamy.

Next, add the eggs and vanilla extract to the sugar-butter mixture. Whisk until it’s light and airy. This step is crucial because it adds volume to our brownies.

In a separate bowl, whisk together the all-purpose flour, cocoa powder, and sea salt. Gradually add this dry mixture to the wet ingredients, mixing gently. You don’t want to overmix; just stir until everything is combined.

Take about ¾ of the chocolate chunks and fold them in gently. These ooey-gooey bites will yield pockets of chocolate in every bite.

Now comes the fun part: taking your smooth peanut butter and dolloping it on top of the brownie batter. Using a knife or a skewer, gently swirl the peanut butter into the batter to create a marbled effect.

Pour the brownie batter into the prepared baking pan and spread it evenly. Sprinkle the remaining chocolate chunks on top. Then, pop it in the oven for about 25 to 30 minutes. You want a toothpick to come out with a few moist crumbs when you check for doneness.

Once out of the oven, let the brownies cool in the pan on a wire rack. Once cool, you can drizzle chocolate on top for a finishing touch. Cut them into squares and enjoy!