Preheat oven to 350 degrees. Line the bottom of a 9x13 inch cake pan with aluminum foil, allowing 2 to 3 inches to extend over sides; lightly grease or spray foil with non-stick spray. (For thicker brownies, use an 8x11.5 cake pan and add an additional 5 minutes to cook time.)
Melt chocolate and butter in a large microwave-safe bowl (for melting chocolate tips read here). Whisk in sugar until all combined. Stir in eggs one at a time until just blended. Stir in flour and next 4 ingredients. Pour mixture into prepared pan.
Bake at 350 degrees for 25 to 30 minutes or until wooden pick inserted in center comes out with a few moist crumbs. Cool completely on a wire rack (about 2 hours) before frosting.
Lift brownies from pan using foil as handles. Gently remove foil. Spread Cream Cheese Frosting* on top of brownies. Cut into squares. Store in refrigerator.