Really good brownies

This is a very good recipe for brownies AND it doesn't call for baking chocolate which I'm nearly almost always out of. I also LOVE cake recipes where you pour the icing on the hot cake, which always looks shiny and glossy and much more satisfactory than my usual terrifying icing jobs.

Batter:
1 cup butter (seriously, butter. Brownies are dependent on the butter-chocolate combo for their taste.)
2 cups sugar
4 heaping Tbsp. cocoa
4 eggs, beaten
1 cup flour
1 cup walnuts, chopped (I leave these out)
1 tsp. vanilla

Icing:
2 cups icing sugar
2 Tbsp. butter
2 Tbsp. cocoa
2 Tbsp. boiling water
2 tsp. vanilla

Preheat the oven to 350 degrees.
Grease a 9x13 inch baking pan.
Cream butter, sugar, and cocoa into a large bowl. Add beaten eggs and vanilla. Then add flour and fold in walnuts. Spread batter in the greased baking pan and bake for 30 minutes.
The top will appear to be underdone (falls in the middle), but don't overcook. These brownies should be moist and chewy.
While the brownies are baking, mix all the icing ingredients together in a medium bowl with an electric mixer. Ice the brownies immediately after removing from the oven so the icing will melt in a shiny glaze.