Preheat oven to 350 degree F.
Line 13x9 inch cookie sheet with foil and spray with cooking spray
Now line the tray with saltines
Bring butter, sugar, and baking soda to a boil and then boil for 3 minutes (until dark brown)
Pour butter mixture over the saltine crackers
Sprinkle the pecans over top and then bake for 8 minutes
Remove from the oven and turn oven off.
Now sprinkle the chocolate over the top and put back into the still hot oven for 1-2 just to add in the melting of the chocolate.
Remove from the oven and use a spatula to spread the chocolate layer evenly over the top of the crackers
Refrigerate for 1 hour
Remove from the refrigerator, break apart, and enjoy!