Preheat oven to 350°F and spray a 9" x 13" baking pan with non-stick cooking spray or parchment paper.
Combine sugar, melted butter, cocoa powder, vanilla, and eggs and mix well.
2 cups granulated sugar, 1 cup salted butter, 3/4 cup unsweetened cocoa powder, 2 tsp vanilla extract, 4 large eggs
Add flour and salt and mix until just combined.
1 cup all-purpose flour, 1/2 tsp salt
Spread the brownie batter evenly in the bottom of the prepared pan then bake for 30 minutes, or until a toothpick inserted in the middle comes out clean. Allow brownies to cool completely.
Peanut Butter Layer
While brownies are cooling, combine powdered sugar, butter, peanut butter, and milk in a mixing bowl and beat about 2 minutes until it is smooth and fluffy.
2 cups powdered sugar, 1/2 cup creamy peanut butter, 2 TBS milk or cream, 1/2 cup butter
Spread the peanut butter mixture evenly over the cooled brownies.
Melt chocolate chips and butter in the microwave for 30 seconds, stir, then repeat until chips are melted and mixture is smooth. Allow it to cool for 10 minutes, then add 1 tablespoon of milk and mix well. It should be an easily spreadable consistency.
Spread melted chocolate over peanut butter layer then cover and refrigerate until chocolate layer is firm.
Cut into squares and serve! Store any leftovers covered in the refrigerator for up to 1 week.
Make sure the the brownie layer is completely cool before adding the peanut butter or the peanut butter will melt right off.Add a piece of parchment paper to the baking pan before adding in the brownie batter to make it easier to remove the brownies from the pan when you’re ready. This makes them much easier to cut!Make a small batch by halving the recipe and baking these an 8×8 square baking pan for 25-30 minutes instead of the written baking time.Store any leftover chewy peanut butter brownies (if there are any) covered in the fridge for up to a week. You can either eat them chilled directly out of the fridge or let them come to room temperature before enjoying.Freeze leftover brownies. Once brownies are chilled, cut into squares and add into a freezer safe container and store in the freezer for up to three months. When you’re ready to enjoy, let thaw at room temperature for at least 30 minutes before eating.