Ingredients

• 5 ounces semisweet chocolate, chopped
• 2 ounces unsweetened chocolate, chopped
• 1 stick unsalted butter, cut into quarters
• 3 tablespoons cocoa powder
• 1 tablespoon espresso powder
• 1 1/2 tablespoons red food coloring
• 1 tablespoon vinegar
• 3 large eggs
• 1 1/4 cup sugar
• 2 teaspoons vanilla extract
• 1/2 teaspoon salt
• 1 cup flour

Instructions

1. Preheat your oven to 350 degrees and adjust your oven rack to the middle position. Spray an 8-inch glass or metal square pan with nonstick cooking spray. Line pan with foil or parchment paper.
2. In a double boiler, melt the semisweet and unsweetened chocolates and butter, stirring occasionally until smooth. Set aside to cool.
3. In a small bowl, combine cocoa powder, red food coloring, and vinegar until it makes a thick paste.
4. In your stand mixing bowl, whisk together the eggs, sugar, vanilla, and salt until combined. Whisk the warm chocolate mixture into the egg mixture, then add the cocoa paste. Once blended, add in the flour a little at a time until just combined.
5. Pour mixture into the prepared pan, spread into the corners, and level with a spatula. Bake for 35-40 minutes until an inserted toothpick comes out with a small amount of sticky crumbs. Cool on a wire rack or eat warm on a snowy day.

Notes