Do not process the cookie crust too much after adding the butter to the food processor or it will become a paste. It is important to have all the chocolate cheesecake batter ingredients at room temperature before mixing to prevent clumping. You cannot have a smooth cheesecake if any of your ingredients are cold. Scrape the sides of your bowl between every step to ensure that everything is fully incorporated. For the brownie batter, use a little more water than prescribed by the box. We leave the eggs out of the recipe, so a little extra water is needed for the proper consistency.