Melt bittersweet and unsweetened chocolate in microwave (cook for 2 minutes at 50% power, remove and stir. Add another 30 seconds at 50% power and stir again. Continue for 30 second intervals until all chocolate is melted, stirring each time).

Add melted butter to chocolate and stir to blend.

Sift flour, baking powder and salt into small bowl and set aside.

In large bowl of electric mixer add eggs and sugar. Beat until creamy and thick, about 5 minutes. Mix in instant espresso powder and vanilla.

Fold in melted chocolate.

Fold in dry ingredients, then stir in chocolate chips and nuts. The batter will be thin.

Drop by heaping tablespoons onto prepared sheet pans, spacing evenly. These will spread but not a lot so you should be able to fit 12 on a sheet.

Bake until the tops are cracked, slightly shiny and soft to touch, about 15 minutes. Cool cookies for a few minutes on pan before removing to cooling rack. Enjoy!