Preheat your oven to 350°F (175°C) and prepare a 9×13-inch baking pan by greasing it or lining it with parchment paper.

In a large mixing bowl, combine the granulated sugar, brown sugar, and vegetable oil. Stir until well blended.

Crack in the eggs one at a time and add the vanilla extract. Whisk vigorously to incorporate air into the batter.

In a separate bowl, sift together the all-purpose flour, cocoa powder, baking powder, and salt. Slowly incorporate this mixture into the wet ingredients, folding gently until just combined.

In a small microwave-safe bowl, warm the peanut butter until creamy, then spread half of the brownie batter evenly in the prepared pan.

Drizzle a generous amount of caramel sauce on top and dollop the warm peanut butter over it.

Add the remaining brownie batter on top and gently swirl the caramel and peanut butter into the batter with a knife.

Bake in the preheated oven for 25-30 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs.

Allow the brownies to cool in the pan for about 10 minutes before lifting them out (if using parchment paper) and letting them cool completely on a wire rack.

Once completely cool, slice into squares and enjoy!