Preheat oven to 350 degrees F. Line an 8-inch square baking pan with parchment paper, leaving overhang on two sides for easy lifting. Lightly grease exposed sides.

In a medium saucepan over low heat, combine butter, 1 cup chocolate chips, and cocoa powder. Stir constantly until melted and smooth, about 3-4 minutes. Remove from heat and let cool 5 minutes so eggs don't scramble.

Whisk sugar into the warm chocolate mixture until fully incorporated. Add eggs one at a time, whisking well after each, then stir in vanilla. The batter should look glossy and thick.

Add almond flour and salt. Switch to a spatula and fold gently until no dry streaks remain. Do not overmix - this keeps the texture fudgy rather than cakey.

Spread batter evenly in prepared pan. Sprinkle remaining 1/4 cup chocolate chips on top. Bake 22-25 minutes until the top is set and crackly but a toothpick inserted in center comes out with moist crumbs, not wet batter.

Cool completely in pan on a wire rack, at least 1 hour. Lift out using parchment overhang, cut into 16 squares with a sharp knife. For cleanest cuts, wipe knife between slices.