Preheat oven to 350 degrees F.Butter a 12 x 18 x 1-inch baking sheet and put a dusting of cocoa powder (or flour) on it.
Melt the butter, 1 bag plus one cup of chocolate chips, and the unsweetened chocolate in a medium bowl over simmering water. Allow to cool slightly.
Meanwhile, in a large bowl, stir (do not beat) together the eggs, coffee granules, vanilla, and sugar.Stir the chocolate mixture into the egg mixture and allow to cool to room temperature.
In a medium bowl, sift together 1 cup of flour, the baking powder, and salt. Add to the cooled chocolate mixture.
Toss 12 ounces of chocolate chips in a medium bowl with 1/4 cup of flour, then fold them into the chocolate mixture.
Pour onto prepared baking sheet. Bake for 20 minutes, then rap the baking sheet against the oven shelf to eliminate any air bubbles.
Bake for about 15 minutes longer or until a toothpick comes out clean. Be careful not to over-bake these brownies.
Allow to cool thoroughly before cutting into squares.
Notes
Candy Bars: Add some of your favorites cut into chunks, such as milky ways or other fun ones.
Peanut Butter: Try to make the brownies with peanut butter chips or swirl in some peanut butter.
Marshmallows: Try cutting up some marshmallows or mini marshmallows into these easy homemade brownies.
Cookies: Feel free to add crushed cookies. Oreos or whatever you wish.
Caramel: Squares of caramel, caramel syrup or sauce.