Melt unsweetened chocolate, 1 cup of the chocolate chips, and the butter stirring occasionally until smooth. Remove from heat and cool. In a large bowl, whip eggs and sugar until thick and pale, about 2 minutes. Stir in vanilla and the chocolate mixture until well mixed. Combine the flour, cocoa, baking powder and salt; gradually stir into the chocolate mixture. Fold in remaining 1 cup chocolate chips. Cover + chill for an hour.
Roll into 1 inch balls. Place 2 inches apart. Bake 350 F for 9 to 11 minutes.