Heat oven to 350 degrees F. Butter an 8" square baking pan.
Melt butter with chocolate in a medium saucepan over low heat; stir until smooth Remove from heat.
In a large bowl, whisk eggs with sugar until pale and thick. Stir in the warm chocolate-butter mixture. Sift flour with baking powder and salt into a separate bowl, and stir into the chocolate mixture. Stir in nuts. Pour into the pan, and bake until the brownies are set and a tester stuck in the center comes out clean, 30 to 40 minutes. Let cool,
and cut into squaresMakes 12
