Over the years I've tried several brownie recipes, but this is the one I've found to be the best. I add chocolate chips to it for that extra burst of chocolate taste (you can never have too much chocolate).
Ingredients: 1/2 stick butter, 2/3 cup shortening (I use butter-flavored), 4 eggs, 2 cups granulated sugar, 2 teaspoons vanilla, 1/3 teaspoon salt, 1 1/3 cups flour, 3/4 - 1 cup cocoa, 1 cup chopped walnuts (optional), 1-2 cups chocolate chips.
Instructions: Preheat oven to 325 degrees. Spray a 9 x 13 inch pan with cooking spray; set aside. Melt together butter and shortening in microwave; allow to cool slightly. In large mixing bowl, beat eggs, sugar, and vanilla; blend in butter mixture and thoroughly combine. Add flour, salt and cocoa and mix well. By hand, stir in chocolate chips (save a handful for the top) and nuts, if desired.
Scrape into the prepared pan and spread evenly with spatula. Sprinkle with the reserved chocolate chips and pop into the preheated 325 degree oven. Bake for 45-50 minutes or until a toothpick inserted in middle brings out only a few crumbs. Remove from oven and allow to cool on rack until cool enough to cut out a square and eat while still warm, but not mouth-burning hot.
I made a batch of these real early in the morning once because I woke up and couldn't get back to sleep. My husband still talks about waking up to the smell of brownies baking; what could be better?