Years ago I worked with this remarkable lady who blessed everyone she knew with her simple, southern cooking. It was such a treat to eat Mrs. Billie's cooking and one of her specalities was brownies. This is witten just like she gave it it me. She would tell everyone when baking to use the best & finest sugar available as that was important to the end result in baking most desserts.
Preheat oven to 325°. Grease and flour pan (I now spray mine with cooking spray). Melt butter and put into mixing bowl, add cocoa to melted butter, mix well. Then add sugar to mixture and blend well. Then add slightly beaten eggs and vanilla, mix well. Now add the flour and nuts to mixture and mix only until the flour and nuts are mixed in well. Don't over stir. Pour mixture into pan. Now, it depends on your oven as to how long to cook them. My oven cooks fairly hot, so if I make an 8 x 8 pan, it takes about 25 minutes or 30 - 35 minutes for a 9 x 13 pan. (The recipe actually says 40 minutes, but I find that's too long in my oven) Mrs. Billie would stress DO NOT OVERBAKE, that is the key to success with brownies! Remove from oven when they 1st look done.