http://www.epicurious.com/recipes/food/views/Brownies-108700

except I use only 1.5 cups sugar, and I replace 1/2 cup of flour with cocoa powder.

2 sticks (1 cup) unsalted butter
226g 8 ounces chocolate chips
86g 3/4 cups all-purpose flour
56g 1/2 cup cocoa powder
4g 1 teaspoon baking powder
4g 1/2 teaspoon salt
310g 1 1/2 cups sugar
4 large eggs
12g 2 teaspoons vanilla

These are delicious, and fairly fast to put together, though they bake for quite a while. Adding orange zest, or cinnamon is quite tasty, and I might try adding Turkish ground coffee (a really REALLY small quantity!) at some point.

https://plus.google.com/u/0/115622514509748938988/posts/H3FKFdrTqDd

Put oven rack in middle position and preheat oven to 350°F. Grease a 9-inch square baking pan (2 inches deep) and line bottom and sides with wax paper, then butter paper.
Melt butter and chocolate in a medium heatproof bowl set over a saucepan of simmering water, stirring occasionally, until smooth.
Whisk together flour, cocoa powder, baking powder, and salt in a small bowl.
Whisk together sugar, eggs, and vanilla in a large bowl, then pour in chocolate mixture, whisking until combined well. Whisk in flour mixture, then stir in walnuts and transfer batter to baking pan.
Bake until top is shiny and set and sides have begun to pull away slightly (a wooden pick or skewer will not come out clean), about 35 minutes, for fudgy brownies; or until wooden pick or skewer comes out clean, 50 minutes to 1 hour total, for cakey brownies.
Cool brownies completely in pan on a rack. Invert onto a cutting board, remove paper, and cut into squares.