1/2 teaspoon salt
1/2 teaspoon baking powder
2 ounces unsweetened chocolate
4 ounces bittersweet or semisweet chocolate
10 tablespoons (1 stick plus 2 tablespoons) unsalted butter
1 1/4 cups sugar
2 teaspoons vanilla extract
3 large eggs
1. Adjust oven rack to lower-middle position and then preheat oven to 325 degrees.
2. Whisk flour, salt and baking powder in a small bowl; set aside. Spray an 8-inch baking pan with cooking spray. Fit a sheet of non-stick foil in pan and up two sides, so you can use it as a handle to pull cooked brownies from pan.
3. Melt chocolates and butter in a medium bowl over a pan of simmering water. Remove from heat; whisk in sugar and vanilla. Whisk in eggs, one at a time, fully incorporating each one before adding the next. Continue to whisk until mixture is completely smooth and glossy. Add dry ingredients, whisk until just incorporated.
4. Pour batter into prepared pan; bake until a toothpick or cake tester inserted in center comes out with wet crumbs, 35-45 minutes (we usually take our pan out at 38 minutes exactly! Also, if you wait until the toothpick comes out clean, the brownies will be overcooked!)
5. Cool brownies in pan on a wire rack for five minutes. Use handles to pull brownies from pan. Completely cool brownies on rack, at least three hours. Cut into squares and serve. If not serving immediately, do not cut brownies. Whole brownie cake can be wrapped in plastic wrap, then foil, and refrigerated for up to five days.
Notes: Sometimes we mix up the chocolate called for in the recipe. We've tried everything from dark chocolate and milk chocolate to milk chocolate and semi-sweet combos. We've found that, at minimum, using unsweetened or at least the darkest chocolate we can find is a must for our perfect brownie. :)