In a medium bowl combine walnuts and 2 Cups chocolate chips and 1/4 Cup flour. Toss to combine, set aside.
Pre heat oven to 350 degrees F. Grease and flour a 13X18 sheet pan
Melt together the butter, chocolate chips and unsweetened chocolate on top of a double boiler. cool slightly.
Stir together the eggs, instant coffee, vanilla and sugar.
Stir in the warm chocolate mixture and cool to room temperature.
Stir together the flour, baking powder and salt.
Add the chocolate mixture. Stir in the reserved nuts, chocolate chips and flour.
Pour into prepared pan.
Bake for 30 minutes--halfway through the baking rap the pan against the oven shelf to allow air to escape from between the pan and the brownie dough.
DO NOT OVER BAKE!!
Cool thoroughly. Refrigerate and then cut into squares.