Gluten-free flour plus a mixture of whipped eggs and sugar help keep the texture both light and fudgy at the same time. Makes sure to use a really good cocoa powder. I haven't tested with natural yet. So far I've only made these with Rodelle brand Dutch. For the chips I've tested with Guittard semisweet and Nestle's new "dark" chips.
4ouncesunsalted butter, cut into chunks(114 grams)
1 ½ouncesunsweetened chocolate, chopped(42 grams)
4 ½tablespoonsunsweetened cocoa powder(25 grams) -- Best to weigh, since cocoa varies. Dutch usually weighs a little more.
3tablespoonsdark chocolate chips (or semisweet Guittard)(28 grams or 1 ounce)
1cup ultra-fine or granulated sugar(7 oz/200 grams)
2largeeggs
¼teaspoonsalt
1teaspoonvanilla extract
60gramsKing Arthur gluten-free flour (see note about brands)(⅓ cup or ⅓ cup plus 2 T based on brand)
Another 3 tablespoons or so dark chocolate chips
Instructions
Preheat oven to 350 degrees F. Line the inside of an 8-inch square metal pan with nonstick foil or parchment paper.
Melt the butter in a saucepan set over medium heat. When it is about halfway melted, add the chocolate and reduce heat to low. Stir until chocolate melts, then stir in the cocoa powder and the 3 tablespoons (28 grams) of chocolate chips. Stir until melted and smooth.
Stir in only ½ cup of the sugar and remove from heat.
Put the eggs in the bowl of a stand mixer and beat with the whisk attachment for about a minute. With mixer going, add remaining ½ cup sugar and continue beating for about 5 minutes or until mixture is pale and thick and falls off the whisk attachment in ribbons. Beat in the salt and vanilla.
Fold about ⅓ cup of the egg mixture into the warm chocolate mixture, then fold the chocolate mixture back into the bowl with the egg mixture. Stir in the gluten free flour.
Spread batter in pan and sprinkle chocolate chips on top.
Bake for 25-27 minutes or until top appears set. Remove from oven and let cool completely. Lift from pan and cut into squares.
Notes
I've also made these with Bob's Red Mill All-Purpose Gluten Free Blend. That flour is a little fluffier and requires about ⅓ cup plus 3 tablespoons to make the requisite 60 grams (2.1 oz by weight). Since posting this I've also tested with King Arthur's Measure for Measure, which also requires more than ⅓ cup to hit 60 grams. For best results, weigh the flour.