Preheat oven to 350. Coat a 12 cup bundt or tube pan with cooking spray. Mix cocoa and chopped chocolate in a heatproof bowl. Pour boiling water over the chocolates and stir until melted. Let the mixture stand to cool. Meanwhile, combine the flour, salt and baking soda. Cream the butter, brown sugar and vanilla until creamy. Add the eggs to the butter mixture and blend well. Fold in the sour cream to cooled chocolate mixture and stir until incorporated. Add the flour mixture and the sour cream/chocolate mixture to the butter mixture until incorporated. Add the chocolate chips to the batter and stir to incorporate. Pour batter into prepared pan and bake for 55 minutes test until toothpick comes out clean. Cool cake in pan before removing. Sprinkle with powdered sugar or ice it or glaze whichever you like.
I used dark chocolate but you can also use bittersweet chocolate squares. My family loves dark choc. This cake also freezes well w/o glazing. Glaze after defrosting if desired or frost or powered sugar.