Peanut Butter Brownies are a decadent dessert that blends the rich, fudgy texture of classic chocolate brownies with the creamy, nutty flavor of peanut butter. They often feature a beautiful marbled or swirled pattern on top, created by mixing peanut butter into the brownie batter. Some versions include peanut butter chips, chocolate chunks, or even a layer of peanut butter frosting for added indulgence.