Melt unsweetened chocolate, bittersweet chips and butter in double boiler,stirring often until smooth. Set aside to cool slightly.
Stir coffee powder and vanilla together in small bowl intil dissolved. Beat eggs and sugar in electric mixer on medium-high speed for 4 minutes until thick and pale in color. Add vanilla-coffee mixture and beat until incorporated, about 20 seconds.
Whisk flour, baking powder and salt together in a medium bowl. Using a large rubber spatula, fold flour mixture and semisweet chips into batter. Cover bowl with plastic wrap and let stand at room temp for 20-30 minutes until batter firms up.
Meanwhile, adjust 2 oven racks to upper and lower position and heat oven to 350 degrees. Line two large baking sheets with parchment paper. Using 1 heaping tablespoon batter per cookie, place cookies 2 inches apart on prepared baking sheets. Bake until cookies are shiny and cracked on top, 11-14 minutes rotating baking sheets top to bottom and front to back half way through baking time. Allow cookies to cool completey on sheets before removal.