Preheat oven to 350 degrees F (177 degrees C) and place the rack in the center of the oven. Butter (or spray with a nonstick cooking spray) a 9 x 13 inch (23 x 33 cm) pan and then line the bottom of the pan with parchment paper.

Melt the chocolate and butter in a stainless steel bowl placed over a saucepan of simmering water. Remove from heat and set aside.

Meanwhile, in a large bowl whisk (or use a hand mixer) together the eggs and sugar. Fold in the melted chocolate mixture and vanilla extract.

In a separate bowl, whisk together the flour, baking powder, and salt and then fold into the chocolate and sugar mixture until well combined.

Pour into the prepared pan and bake for about 40 - 50 minutes, or until a toothpick inserted in the center comes out with just a few moist crumbs. Remove from oven and let cool on a wire rack. Serve at room temperature or chilled. Store leftovers in the refrigerator. These freeze very well.

Makes 24 - 2 inch (5 cm) brownies.

1 1/2 pounds (680 grams) semisweet or bittersweet chocolate, chopped

1 cup (2 sticks) (226 grams) unsalted butter, cut into pieces

6 large eggs

2 cups (400 grams) granulated white sugar

1 tablespoon pure vanilla extract

1 1/2 cups (210 grams) all-purpose flour

1 teaspoon baking powder

1/4 teaspoon salt