Place walnuts and 2 Cups of the chocolate chips in a bowl and toss with 1/4 cup of flour, set aside.
Pre heat oven to 350
Grease and flour a 13X18 inch sheet pan
Melt together the butter, chocolate chips, unsweetened chocolate on top of a double boiler. (or in a bowl set over a pan of simmering water.)
Stir together eggs, instant coffee, vanilla and sugar.
Stir in the warm chocolate mixture and cool to room temperature.
In another bowl stir together flour, baking powder and salt.
Add the cooled chocolate mixture.
Stir in the nuts and chocolate that have been dusted with the flour.
Pour into pan.
Bake for 30 minutes.
Halfway through baking, rap the pan against the oven rack to allow air to escape from between the brownie dough and the pan.
Do Not Over Bake!!!!
Refrigerate and then cut into squares.
These do cut much easier when cold.
They are moist enough that if you wish a warm brownie zap for a few seconds in the microwave.