Martha Stewart, *with one addition
6 tablespoons unsalted butter, plus more for pan
6 ounces semisweet chocolate, coarsely chopped (1 1/2 Godiva bars)
1/4 cup unsweetened Dutch-process cocoa powder
3/4 cup flour
1/4 teaspoon baking poweder
1/4 teaspoon coarse salt
1 cup sugar
2 large eggs
2 teaspoons pure vanilla extract
1 cup milk chocolate chips (*optional, but highly recommended)
Preheat oven to 350 degrees F, line a buttered 8-in square baking pan with parchment paper, leaving an overhang (so that you can lift the brownies out) and grease the parchment paper.
Melt chocolate, butter, & cocoa powder in a double boiler, or a bowl set over simmering water. Let cool slightly.
In a small bowl whisk together flour, baking powder & salt. Set aside.
In a large bowl, whisk sugar, eggs & vanilla until pale. Add chocolate mixture and stir to combine. If your chocolate mixture is still quite warm, pour a bit of the egg mixture into it, stir well, and then add all of the chocolate to the egg mixture. Add flour and stir until well combined.
Bake for about 35 minutes, let cool in pan, about 15 minutes, then lift out of pan onto a cooling rack, let cool completely before cutting into squares.