Preheat the oven to 325F. Grab an 8x8ish baking pan and grease it WELL -- I ain't whistling Dixie, here. Get serious with the grease and make sure to do the sides as well. No slacking allowed.

Melt the butter. Combine sugar, cocoa, salt, vanilla and any spices and cream together. 

Test to make sure the mixture is cool enough (ie. doesn't burn your fingers when you stick them in it) and add eggs, flour and nuts if you're going that route. Mix well.

Spread evenly in the lined pan. The batter will be sticky and clumpy and the consistency of chocolate chip cookie dough. Don't panic!

Bake until a toothpick plunged into the center emerges slightly moist with batter, 20 to 25 minutes. Let cool at least until you no longer burn your fingers before you try to eat them, even though they smell like something otherworldly.