Preheat oven to 325 - that's right not, 350, these need to cook at a lower temperature than usual. Grease or butter an 8 inch square baking pan.
Boil water in a saucepan, and place a bowl with the chopped chocolate over it to melt the chocolate. This method ensures the chocolate melts nicely and doesn't seize up or burn.
Melt the butter in a good sized sauce pan. Remove from the heat and let it cool down for 10 minutes. Add the cocoa powder, melted chocolate, bourbon, vanilla, salt and sugar and mix well.
Add the eggs, one at a time and stir with a wooden spoon to incorporate.
Add the flour last and fold it in, just to combine. Note: if you are adding nuts, this would be where you would add them - with the flour.
Do not use a whisk or a stand or hand held mixer for this recipe. By hand and gently only.
Bake on the middle rack for about 35 minutes. Here is the thing with brownies to achieve max fudginess...they might look not totally done, the center might be a little jiggly. That is ok, they will continue to cook slightly when you take them out. My biggest tip for this is to cook for exactly 35 minutes, after 35 minutes, shut the oven off, crack it open and let them sit in there to come down to temp for 25 minutes. Then remove from oven and cool on a wire rack completely.