Creating Peanut Butter Stuffed Brownies can be straightforward if you follow these simple steps:

1. Preheat Your Oven: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan or line it with parchment paper for easy removal.
2. Mix Butter and Sugar: In a large mixing bowl, combine the melted butter and granulated sugar. Mix well until smooth.
3. Add Eggs and Vanilla: Beat in the eggs one at a time, mixing thoroughly after each addition. Then, stir in the vanilla extract.
4. Combine Dry Ingredients: In a separate bowl, whisk together the flour, cocoa powder, baking powder, and salt.
5. Combine Mixtures: Gradually add the dry ingredients to the wet mixture, stirring until just combined. Be careful not to overmix.
6. Prepare Peanut Butter Filling: In a small bowl, mix the creamy peanut butter with powdered sugar until smooth and well combined.
7. Layer the Mixture: Pour half of the brownie batter into the prepared pan, spreading it evenly. Spoon the peanut butter mixture over the brownie batter, spreading it out. Finally, pour the remaining brownie batter over the peanut butter layer, spreading it gently.
8. Bake: Place in the preheated oven and bake for 25-30 minutes or until a toothpick inserted into the center comes out with a few moist crumbs.
9. Cool: Remove from the oven and allow the brownies to cool in the pan for about 15-20 minutes before cutting them into squares.
10. Serve Warm or Cool: For the best experience, serve the brownies slightly warm, allowing the peanut butter filling to be soft and gooey.