Adapted from How Can it Be Gluten Free by Americas Test Kitchen
- 4 ounces (3/4 cup plus 2 tablespoons) ATK All-Purpose gluten-free flour blend
- 1/2 teaspoon fine salt
- 1/2 teaspoon xanthan gum
- 7 ounces chopped semisweet chocolate (I use chocolate chips)
- 8 tablespoons (1/2 cup) unsalted butter, cut into cubes (I use salted butter)
- 3 tablespoons unsweetened cocoa powder
- 8 3/4 ounces (1 1/4 cup) granulated sugar
- 3 large eggs
- 2 teaspoons vanilla extract
- Line or grease an 8×8 inch baking pan. Wait to pre-heat oven as batter will need to rest for 30 minutes.
- In a medium bowl, whisk together the GF flour blend, salt, and xanthan gum.
- Mix in eggs, sugar, and vanilla extract.
- In a microwaveable bowl, combine the chocolate, butter, and cocoa powder. Microwave for 1 to 3 minutes, stirring each minute, until melted and smooth. Set aside to cool slightly.
- Whisk the chocolate mixture into the flour mixture until well combined.
- Immediately pour batter into prepared pan and smooth the top with a spatula. Cover, and allow to rest 30 minutes.
- About 15 minutes before you’re ready to bake, set an oven rack in the middle position and heat oven to 350-F.
- Bake 45-55 minutes or until a toothpick inserted into the center comes out with a few moist crumbs attached.
- Allow to cool for 2 hours on rack (I let mine cool for 15 minutes and they were perfect).
- Store in an airtight container at room temperature for 2 days, or in the fridge.
