For the Brownies:
Preheat oven to 400 and grease a 17x11 jelly roll pan (or large baking sheet with a rim).
In the bowl of your mixer combine flour and sugar.
In a heavy saucepan combine butter, shortening, coffee or water, and cocoa powder. Stir and heat to boiling.
Pour boiling mixture over the flour/sugar mixture. Add the rest of the ingredients. Mix well.
Pour into prepared pan. Place chocolate throughout the pan and bake at 400 for 20 minutes.
For the Glaze:
While the brownies bake prepare frosting. In a saucepan combine butter, cocoa powder, and milk. Heat to boiling, stirring.
Mix in the powdered sugar and vanilla until the glaze is smooth. Remove from heat.
Pour warm frosting over brownies as soon as you take them out of the oven. Cool and serve.