Ingredients
1 stick unsalted butter, cut into tablespoons, plus more for pan
6 ounces bittersweet chocolate, preferably 70 percent cacao, chopped (about 1 1/4 cups)
3/4 cup granulated sugar
3/4 cup packed light-brown sugar
3 large eggs, room temperature
1/4 cup unsweetened cocoa powder
1/2 teaspoon coarse salt
3/4 cup spelt flour
Preparation
Preheat oven to 350 degrees. Lightly brush an 8-inch square baking pan with butter. Line with parchment, leaving a slight overhang on 2 sides. Butter parchment.
Place butter and chocolate in a large heatproof bowl set over a saucepan of simmering water and melt, stirring, until smooth. Remove from heat and whisk in sugars. Whisk in eggs, 1 at a time, until combined. Whisk in cocoa and salt, then fold in flour until combined.
Pour batter into pan and bake until a toothpick inserted in center comes out with moist crumbs, about 35 minutes. Let cool completely in pan on a wire rack. Lift out brownies with parchment overhang. Cut into 16 squares.
