What you need:

Equipment: Hand or stand mixer, 9X13 baking pan, wooden spoon, spatula

• 1 cup or 2 sticks butter, melted
• 3/4 cup baking cocoa
• Two cups of granulated sugar (You can cut back on the sugar if two cups are too much).
• 4 eggs 
• 1 cup all-purpose flour
• 2 teaspoons vanilla extract
• 1/2 teaspoon salt
• 2 cups semisweet chocolate chunks broken into small pieces 
• 1 cup chopped walnuts (optional)

Method:

1. Preheat oven to 350 degrees F. Coat a 9- x 13-inch baking dish with cooking spray.
2.  
3. Place softened butter in a large bowl; add cocoa and stir until well blended. Add sugar; mix well. Add eggs, one at a time. Beating well after each addition. Add flour, vanilla, and salt; stir just until combined. Stir in chocolate chunks and nuts, if desired—spread batter in baking dish.
4.  
5. Bake about 40 minutes, or until a toothpick inserted in the center comes out clean. Let cool, then cut into serving-sized pieces.