Gluten-Free Fudge Brownies

Preheat oven to 350°. Line a 13x9" baking pan with parchment paper, leaving a generous overhang on all sides. Toast pecans on a rimmed baking sheet, stirring occasionally, until slightly darkened and fragrant, 8–10 minutes. Let cool; chop.

Chop 1 pound chocolate and heat with butter in a heatproof bowl set over a saucepan of simmering water (bowl should not touch water), stirring, until butter and chocolate are melted and mixture is smooth. Let cool slightly.

Whisk flour, baking powder and salt in a small bowl. Using an electric mixer on medium-high speed, beat eggs, sugar, and vanilla in a large bowl until mixture is pale and thick, 6–8 minutes. Reduce speed to low and add dry ingredients, mixing just to combine. Mix in chocolate mixture.

Chop remaining chocolate. Using a wooden spoon or rubber spatula, fold in chopped chocolate and two-thirds of pecans. Scrape batter into prepared baking pan and sprinkle with remaining pecans. Bake brownie until puffed and top is cracked and looks dry and shiny, 30–35 minutes. Let cool before cutting into 2" squares.

DO AHEAD: Brownies can be made 5 days ahead. Store tightly wrapped at room temperature.