Directions 15 steps | 95 Minutes
Preheat the oven to 350°F. Grease and line a 9x13-inch baking pan with parchment paper. In a microwave safe bowl, add the butter, oil, dark brown sugar and granulated sugar.
Microwave on high for 30 seconds and stir. Continue to microwave in 15 second intervals and stir until the butter is melted.
Stir in the extra-large eggs, egg yolks and vanilla extract.
Add the all-purpose flour, Dutch-processed cocoa powder, instant espresso powder and salt. Stir until just combined.
Transfer the batter to the prepared baking pan and smooth out the batter with an offset spatula.
Bake for 25-30 minutes, until a toothpick inserted into the center comes out with just a few crumbs attached. Let the brownies cool completely on a wire rack while you prepare the peanut butter filling.
In a mixing bowl, use an electric mixer to beat the creamy peanut butter, softened butter and salt until well combined.
Beat in the powdered sugar and whole milk in alternating additions until smooth.
Beat in the vanilla extract until well combined.
Evenly spread the peanut butter filling on the completely cooled brownies.
In a microwave-safe bowl, add the heavy cream and finely chopped semi-sweet chocolate. Microwave for 1 minute and let stand for 5 minutes.
Stir until a glossy ganache forms. If the chocolate did not melt enough, microwave in 10-second intervals until smooth.
Stir in the creamy peanut butter and mix until smooth.
Spread the peanut butter ganache over the peanut butter filling. Refrigerate until the ganache fully sets, at least 30 minutes.
Slice, serve and enjoy!