Preheat & Prepare Pan: Preheat oven to 350°F (175°C). Line a 13×9-inch metal baking pan with foil and lightly spray with cooking spray.
Sift Dry Ingredients: Sift together flour, cocoa powder, and salt in a bowl; set aside.
Whip Eggs & Sugar: In a stand mixer, combine sugar, vanilla extract, espresso powder, and eggs. Beat on medium-high for 7–9 minutes until the mixture is fluffy and pale yellow.
Melt Chocolate & Butter: In a small pan, heat vegetable oil and butter until the butter melts. Remove from heat and stir in dark chocolate until smooth.
Combine Mixtures: Reduce mixer speed to low, gradually add the melted chocolate mixture, then sifted flour mixture. Mix for 1 minute, then fold gently with a spatula to combine.
Bake: Pour batter into the prepared pan and smooth the top. Bake at 350°F for 30–35 minutes.
Cool & Serve: Allow to cool to room temperature. Lift brownies out of the pan using the foil, cut into squares, and enjoy!
Serving and Storage Tips
