Preheat your oven to 350 degrees F. This ensures that the brownies bake evenly and get that perfect texture.
Grease a 9×13 inch baking pan and set it aside. This prevents the brownies from sticking, making it easier to cut and serve them later.
In a saucepan over low heat, melt the butter and semi-sweet chocolate. Stir constantly until smooth, which usually takes a few minutes. It’s important not to let it overheat, or it might scorch.
Remove the pan from heat and stir in the white sugar. This creates a sweet base for your brownies.
Add the eggs one at a time, beating with a whisk after each addition until fully combined. This step incorporates air into the mix, making your brownies lighter.
Now, stir in the vanilla. The aroma of vanilla will enhance the overall flavor profile.
Next, add the all-purpose flour and salt. Stir until the mixture is smooth and well combined. Be careful not to overmix, as this can result in denser brownies.
Pour the brownie batter into the prepared pan, spreading it evenly. This ensures that the brownies bake uniformly.
Bake in the preheated oven for 35 to 40 minutes. Keep an eye on them; they’re done when a toothpick inserted into the center comes out clean.
Once baked, let the brownies cool in the pan for at least 30 to 45 minutes. This cooling period is crucial before adding the peanut butter filling.
Meanwhile, in a microwave-safe bowl, combine the peanut butter and 4 tablespoons of butter. Heat in 30-second intervals, stirring in between, until smooth. It’s important to achieve a creamy consistency for easy spreading.
Add powdered sugar to the mixture and stir until well blended. The filling should be slightly firm yet pliable, resembling soft cookie dough.
Using a rubber spatula, carefully spread the peanut butter layer over the cooled brownies. It can help if the brownies are still slightly warm, as this keeps the peanut butter from ripping them apart.
In a separate microwave-safe dish, heat the semi-sweet chocolate chips at 50% power in 30-second intervals, stirring in between until smooth. Ensure that the chocolate is not overheated, as it can become grainy.
Pour the melted chocolate over the peanut butter layer, using another rubber spatula to spread it evenly.
Let the brownies cool completely, allowing the chocolate layer to set firmly. Enjoy your Peanut Butter Cup Fudge Brownies with a nice big glass of milk!