Number 1 Tip: Allow yourself plenty of time to make this dessert so the layers have time to chill or rest. I like making the brownies a day ahead!Brownies: Preheat oven to 350℉. Line a 9x9-inch (or 8x8-inch for thicker brownies) pan with parchment paper, leaving an overhang. Prepare and bake the brownie mix according to package directions, being careful not to overbake. Let cool for 20 minutes, then cover and place in the fridge (or freezer) while preparing the peanut butter layer.
Peanut Butter Layer: In a large bowl, mix melted butter, peanut butter, vanilla, salt, and powdered sugar until a smooth, thick dough forms. Drop dollops of the mixture over the cooled brownies. Use the back of a spoon to gently spread it into an even layer, pressing it to the edges of the pan. Cover and refrigerate while preparing the topping.
Topping: In a microwave-safe bowl, combine chocolate chips and coconut oil. Microwave in 20-second bursts, stirring in between, until fully melted and smooth. Pour over the peanut butter layer and smooth into an even layer. Let set at room temperature.
Serve: Once topping is firm, use the parchment overhang to lift the brownies from the pan. Cut with a sharp knife, running the blade under hot water and drying between cuts for clean slices. Let sit at room temperature for about 30 minutes before serving.
Notes
Note 1: I use a boxed brownie mix for convenience, but homemade brownies work too! Just make sure your recipe fills an 8x8 or 9x9-inch pan. My go-to mixes are Betty Crocker's Supreme Triple Chunk® (17.8 ounces) or Ghirardelli Ultimate Chocolate Brownie Mix® (19 ounces). I prefer the Betty Crocker mix.Storage: Store brownies in an airtight container in the fridge for 3–4 days for the best taste. Freezing isn’t recommended as the dairy in the filling and topping doesn’t hold up well after thawing.