Brownies:
Prepare one (12 x 18in) baking sheet or two (12 3/4 x 9 in) baking sheets by spraying with non-stick cooking spray.
Fill a medium sized sauce pan with water. Bring to a slow boil. Place a heat resistant mixing bowl on top of the sauce pan. Note: this is a make-shift double boiler. If you have a double-boiler, God love your heart. You can use that instead.
Add butter, one pound (16 ounces) of chocolate chips, and cocoa powder to the bowl.. Stir until melted.
Remove and let cool for 5 minutes.
Add eggs to a mixing bowl and whisk well. Add a few spoonfuls of the warm chocolate mixture to the eggs to temper the eggs and quickly whisk.
To the egg mixture, whisk in vanilla extract, instant coffee and sugar. Whisk egg mixture into chocolate mixture.
Add 1 1/4 cups flour into chocolate mix. Stir until all the white from the flour is gone.
In a small bowl, stir together remaining 1/4 cup flour, remaining 8 ounces chocolate chips and chopped walnuts until chips and nuts are well coated. Stir into batter.
Pour in prepared pan(s).
Bake in a preheated 350 degree for 35 minutes or until toothpick inserted comes out clean.
Remove from oven and ice while still warm. Let cool completely before cutting.
Icing:
With an electric mixer, mix together ingredients until smooth. Ice brownies while they're still warm.