01 -
Preheat the oven to 350°F. Fit the pie crust into a 9-inch pie plate, crimp the edge, and chill it while you make the filling.
02 -
Combine the butter and chopped semisweet chocolate in a microwave-safe bowl. Heat in 20-second bursts, stirring between each, until smooth. Cool for 5 minutes.
03 -
In a large bowl, whisk the eggs, granulated sugar, and brown sugar for about 1 minute, until glossy and slightly lighter. Whisk in the vanilla.
04 -
Stir the cooled chocolate mixture into the egg mixture. Add the flour, cocoa powder, and salt, then fold just until no dry streaks remain. Fold in the chocolate chips.
05 -
Spread the brownie batter into the chilled pie crust and smooth the top. Sprinkle with flaky salt if using.
06 -
Bake for 35-42 minutes, until the edges are set and puffed but the center still has a slight wobble. A toothpick inserted near the center should come out with moist crumbs.
07 -
Cool for at least 1 hour before slicing. Serve slightly warm or at room temperature with ice cream or whipped cream.