Ingredients
 
							Scale
													 
 - 1 cup all-purpose flour
 - 1 cup unsweetened Dutch process cocoa powder
 - 1 tablespoon cornstarch
 - 1 teaspoon salt
 - 1 ½ cups white granulated sugar
 - ½ cup powdered sugar
 - 3 large eggs, room temperature
 - 1 egg yolk, room temperature
 - ½ cup unsalted butter, melted
 - ½ cup canola or vegetable oil
 - 1 teaspoon pure vanilla extract
 - 1 cup semi-sweet chocolate chips
 - 1 cup Andes peppermint chips
 
Instructions
- Preheat the oven to 350°F (175°C) and prepare a 9×9 inch baking pan.
 - Sift together flour, cocoa powder, cornstarch, and salt in a bowl.
 - Beat together granulated sugar, powdered sugar, eggs, and egg yolk until fluffy.
 - Add melted butter, oil, and vanilla extract to the egg mixture and combine.
 - Gradually mix in the sifted dry ingredients.
 - Fold in chocolate chips and peppermint chips.
 - Pour the batter into the prepared baking pan and spread evenly.
 - Bake for 33-40 minutes until edges are set and center appears slightly underdone.
 - Cool completely before cutting into squares.
 
Notes
Use room temperature eggs for better emulsification.
Do not overbake to maintain a fudgy center.
Store leftovers in an airtight container.
- Prep Time: 15 minutes
 - Cook Time: 40 minutes
 - Category: Dessert
 - Method: Baking
 - Cuisine: American
 
Nutrition
- Calories: 250
 - Sugar: 20g
 - Sodium: 150mg
 - Fat: 12g
 - Saturated Fat: 7g
 - Unsaturated Fat: 4g
 - Trans Fat: 0g
 - Carbohydrates: 34g
 - Fiber: 2g
 - Protein: 3g
 - Cholesterol: 50mg