Bake cake mix according to directions. Cool, crumble, and set aside. In a large mixing bowl, using hands, mix the cream cheese, semi sweet chocolate chips, and crumbled cake together. Form into tablespoon sized balls and place on two cookie sheets lined with parchment. Set in the fridge for 1-2 hours to cool. Or place in the freezer for 30-35 minutes until firm. Melt the chocolate in a double boiler, over the stove, with shortening. Dip the truffles into the chocolate, then place them back on the same cookie sheet. Repeat this until all truffles are coated. Decorate as desired, using sprinkles, crushed Oreo cookies or wafers, finely chopped nuts, or powdered sugar. After decorating, set the truffles in the fridge for an additional hour to cool completely.