Grease 9" x 13" baking pan with butter (a great trick is to use the wrapper from a stick of butter).

Melt butter and then add the sugar to the melted butter.

Add brown sugar and cocoa powder.

Stir together well, making sure to get out the lumps of the cocoa powder (*itcan be quite bitter if you bake it with the lumps).

Add eggs and continue to stir; continue and add flour, and baking powder.

Fold all together then add vanilla.

Transfer mix into baking pan and spread out evenly.

Garnish the top with nuts (if you prefer).

Bake at 350º for 40-45 minutes.

When it's done, it will start to pull away from the sides and it might start to crack; however, the middle should be loose so that your brownies will be nice and chewy.

Remove from pan, and allow it to cool completely.

Cut into squares and enjoy!