2 sticks (=225 gr) butter
2 cups sugar
3/4 cup cocoa powder
3-4 eggs, lightly beaten
1 1/2 cups flour
1 tsp salt
1 tsp baking powder
3/4 cup walnuts (optional)
Grease a 9x13 inch pan. In a bowl, melt butter and then mix in the sugar and cocoa powder. Stir in the eggs, flour, salt and baking powder. When well mixed, stir in walnuts.
Bake at 350F/180C for 30 mins.