In a microwave or double boiler, melt unsweetened chocolate, 1 cup chocolate chips and butter. Cool for 10 minutes. In a mixing bowl, beat sugar and eggs for 2 minutes. Add vanilla and the chocolate mixture and mix well. Combine flour, cocoa, baking powder and salt. Mix into chocolate mixture. Stir in remaining chocolate chips.
Cover dough and refrigerate for at least three hours. Heat oven to 350°. Remove no more than 1 cup of dough from refrigerator at a time. With lightly floured hands (I used disposable plastic gloves), roll into 1" balls. Place on an ungreased cookie sheet. Bake for 10-12 minutes, until lightly puffed and set. Cool for 3-4 minutes, then remove from pan to baking racks to cool completely. Dust with confectioner's sugar.