Yields 24 brownies
1/3 cup superfine brown rice flour
1/3 cup superfine white rice flour
1/3 cup sweet rice flour
1/4 cup tapioca flour
1/4 teaspoon baking powder
1/2 teaspoon salt
6 ounces unsweetened chocolate, broken into pieces
12 tablespoons (1 1/2 sticks) unsalted butter (or 11 tablespoons of coconut oil plus one tablespoon water for a dairy-free option)
2 1/4 cups (15 3/4 ounces) sugar
3 eggs
1 tablespoon vanilla extract
(Note: This recipe works best with the specific gluten-free flours listed, but you can alternately use 1-1/4 cups (5 ounces) of your favorite gluten-free flour. I will not guarantee satisfactory results because I've had many epic failures using other flour blends. The blend I've listed is the best.)
Heat oven to 325 degrees. Spray a 13 by 9-inch baking pan with nonstick cooking spray.
Whisk flour, baking powder, and salt in a medium bowl until combined. Set aside.
Melt chocolate and butter in a medium saucepan over low heat until smooth, stirring frequently to avoid scorching. Remove from heat. (Or microwave in short bursts, stirring until melted and smooth.)
Whisk sugar into chocolate mixture. Add eggs, one at a time, whisking after each addition, until thoroughly combined. Add vanilla. Add chocolate mixture to flour mixture, folding with a rubber spatula until the batter is completely smooth and homogeneous.
Transfer the batter to the prepared pan, spreading the batter evenly with a rubber spatula.
Bake until a toothpick inserted in the center of the brownies comes out with a few moist crumbs attached, 30 to 35 minutes. Allow brownies to cool slightly before serving.