Preparation Steps

• Preheat oven to 350°F (175°C). Grease and flour a 9x13 inch baking pan.
• In a large bowl, cream together the butter and sugar until light and fluffy. Beat in eggs one at a time, then stir in the vanilla.
• In a separate bowl, whisk together the flour, cocoa powder, baking powder, and salt. Gradually add to the wet ingredients, mixing until just combined.
• In a small bowl, combine the peanut butter and powdered sugar. Roll into 12 balls.
• Pour half of the brownie batter into the prepared pan. Place peanut butter balls evenly over the batter. Top with remaining batter.
• Bake for 30-35 minutes, or until a toothpick inserted into the center comes out with moist crumbs.
• Let cool completely before cutting and serving.