Preheat oven to 350°.
Line 2- 8″ x 8″ pans with parchment paper and set aside.
Whisk the flour and salt together in a small bowl and set aside.
Meanwhile, cream the butter and sugar together until light and fluffy.
Beat in the eggs.
Beat in the dry ingredients alternating with the buttermilk and coffee. Do not overmix.
Fold in the chopped chocolate and pour the batter into the prepared pans, distributing as evenly as possible between the two and smoothing the tops.
Bake for 26-28 minutes or until a cake tester inserted in the center of one of the pans comes out clean.
Cool and cut dessert bars, serving immediately or storing in an airtight container for up to 4 days.