Black-Bottom Brownies

Preheat oven to 325°. Lightly coat a 13x9" baking dish with nonstick spray, then line with parchment paper, leaving a 2" overhang on long sides. Coat parchment with nonstick spray. Pulse 1 egg, cream cheese, and ⅓ cup sugar in a food processor, scraping down sides as needed, until smooth.

Whisk cocoa powder, salt, and remaining 2½ cups sugar in a large bowl to combine. Whisking constantly, add butter in a steady stream; whisk in vanilla. Add remaining 4 eggs one at a time, whisking vigorously to blend after each addition.

Add flour and stir until just combined (you don’t want to overmix). Spoon dollops of batter into prepared baking dish. Spoon dollops of cream cheese mixture in between dollops of batter. Run a knife through both mixtures to swirl (you want to create fat ribbons).

Bake until cream cheese mixture is barely golden and a tester inserted into the center of brownie comes out with only a few moist crumbs attached, 35–40 minutes. Transfer pan to a wire rack and let brownie cool.

Use parchment paper overhang to lift brownie out of pan and onto a cutting board. Trim edges; cut brownie into thirty-two 1½" squares.

Do Ahead: Brownies can be made 2 days ahead. Store tightly wrapped at room temperature, or freeze, uncut, up to 1 month.