- 1 pinch unsweetened cocoa powder
- 12 ounces 80% cacao chocolate
- 1 cup unsalted butter
- 4 eggs
- 3/4 cup light brown sugar
- 3/4 cup demerara (turbinado) sugar
- 1 cup all-purpose flour
- 1 teaspoon vanilla extract
- 1/2 teaspoon salt
- Preheat oven to 325 degrees F (165 degrees C). Lightly butter a 9×13-inch baking dish. Sprinkle cocoa powder into the dish.
- Melt chocolate and butter in top of a double boiler over simmering water, stirring frequently and scraping down the sides with a rubber spatula to avoid scorching, about 5 minutes.
- Whisk eggs, brown sugar, and demerara sugar together in a bowl until smooth. Stir chocolate mixture into egg mixture until thoroughly mixed. Stir in flour, vanilla extract, and salt into chocolate-egg mixture until thoroughly mixed; pour into the prepared baking dish.
- Bake in the preheated oven until a toothpick inserted in the center comes out clean, about 35 minutes.