• Preheat to 350°F. then line an 8x8-inch metal pan with parchment and set aside.
• In a heatproof bowl, combine butter, chopped chocolate, and oil. Melt gently (microwave in 30 sec bursts or over a double boiler), then stir in cocoa powder and the espresso powder until smooth. Let it cool slightly.
  ½ cup butter, 3 tablespoon neutral oil, 4 oz 70% dark chocolate, chopped, ⅔ cup Dutch process cocoa powder, 1 teaspoon instant espresso powder
• In a large bowl, beat eggs, yolk, granulated sugar, powdered sugar, and vanilla on high speed for 3-6 minutes until thick, pale, and ribbon-y. This is where that shiny crackle top is born!
  2 large eggs, 1 egg yolk, 1 cup granulated sugar, ½ cup powdered sugar, 1½ teaspoon vanilla extract
• With the mixer on low, slowly pour in the slightly cooled chocolate-butter mixture.
• Sift the dry ingredients into the brownie batter mixture. Gently fold into the batter with a spatula.
  ½ cup all-purpose flour, 1 tablespoon cornstarch, ½ teaspoon kosher salt
• Pour the batter into the prepared pan, smooth the top, and tap the pan once on the counter. Bake 23-25 minutes, or until a toothpick comes out with moist crumbs
• Let the brownies cool fully in pan for a little bit before adding the toppings.

Peanut butter layer

• In a medium bowl, whip together the softened butter and peanut butter using a hand mixer until smooth and fluffy.
  5 tablespoon butter, ¾ cup peanut butter
• Add the powdered sugar, vanilla extract, and salt, and mix until the mixture becomes crumbly but cohesive, it should hold together when pressed.
  1 & ½ cup powdered sugar, ½ teaspoon vanilla extract, ¼ teaspoon salt
• Once the brownies have cooled, crumble the peanut butter mixture over the cooled down brownie then press that mixture evenly over the surface of the brownies. Use a piece of wax paper or parchment paper to help press it down smoothly and evenly without sticking.

Make the chocolate topping

• In a microwave-safe bowl, melt the butter and chocolate chips in 20–30 second intervals, stirring between each, until smooth and glossy. Let it cool for about 5 minutes so it doesn’t melt the peanut butter layer.
  5 tablespoon butter, 1 cup semi-sweet chocolate chips
• Pour the melted chocolate over the peanut butter layer and spread it out gently with an offset spatula. If desired, drizzle some extra melted peanut butter over the top for a pretty swirl or decorative finish.
• Refrigerate the brownies for about 30–60 minutes to set the layers before slicing. Store in the fridge for the cleanest cuts!