Preheat oven to 375. Line cookie sheet with parchment paper.
Sift together flour, baking powder and soda and salt, set aside.
Melt shortening and chocolate together, either on the stove top or in the microwave. Let cool for 10 minutes. Stir in brown sugar, egg, vanilla and buttermilk. Add flour mixture and mix well. If using nuts and chips add them now.
Drop by spoon full onto parchment lined baking sheet, I personally use a medium sized cookie scoop*. Bake for about 10 minutes. Transfer to cooling rack and frost with mocha frosting when cooled. This is a soft cookie, and buttermilk is what makes it so nice and soft.
For Mocha Icing combine all items in mixing bowl and beat with an electric mixer till light and fluffy, about 7 minutes. Add milk or cream if needed to thin icing.
*See Sur La Table's web site or any cooking supply store or website if your looking for a scoop. You want a good quality scoop and it will last you for years to come.