• Don't even try to substitute the butter here.  Besides, are you pretending to be healthy or something?  Yes?  This is so not the recipe for you.
• The dough may seem softer than normal cookie dough (before you add in the chocolate chips and the nuts).  Do not fret.  Once the other things are tossed in, they will be just fine.  If you need to, you can up your flour a tad (I just use a heaping 1/2 cup).  But try to resist the urge unless you really feel the need.
• 2 cups of nuts may seem like a lot.  And it is.  But it is necessary (at least in my opinion).  The cookie is so insanely chocolatey, that the nuts are a welcomed offset.  They help you find a small sliver of balance in flavors.
• Dough does not spread like normal cookies (where you can put a heap on a cookie sheet, and it spreads/flattens out).  This means you can place cookies closer together, however if - when dropping scoops onto the cookie sheet - you find your mounds of dough pretty high, use the back of your measuring cup to flatten them down somewhat.

INGREDIENTS

    1 pkg (8oz) Baker's semi-sweet baking chocolate, roughly chopped
    3/4 Cup Brown Sugar, packed
    1/4 C Butter, softened
    2 Eggs
    1 tsp Vanilla
    1/2+ Cup of flour (see note)
    1/2 tsp Baking Powder
    8oz Semi-sweet Chocolate Chips
    2 Cups Pecans, chopped (or Walnuts)

DIRECTIONS

• Pre-heat oven to 350 F.
• Place chopped baking chocolate in a large mixing (and microwave-safe) bowl, and microwave in 1-min increments until melted.  Stir between each set minute.
• Stir brown sugar and butter into melted chocolate. 
• Stir in eggs and vanilla, then stir in flour and baking powder.
• Stir in chocolate chips and pecans.
• Using a 1/4 Cup measuring cup, scoop cookie dough onto ungreased cookie sheet. 
• Bake at 350 F for 12 - 15 minutes.
• Let sit 1 minute on cookie sheet before transfering to wire cooling rack for cooling. 

Recipe Origins: From 2002 Baker's Chocolate mini cooking book.