You'll Need: 13 x 9 Baking Pan Oreos Nonstick foil-best creation ever! Chocolate Oreo Cake Gooey Bars Ingredients 8 tablespoons butter, melted, plus 8 more tablespoons butter, melted 1 (18.25-ounce) package chocolate cake mix 1 egg, plus 2 eggs 8 ounces cream cheese, softened 4 tablespoons cocoa powder 16-ounces powdered sugar 1 teaspoon vanilla extract