Hello In my opinion the correct phrase is The mall closes at 9:00 pm . Because it is a schedule , I mean its something that always happens. If you talk about habits or schedules you have to use Simple Present.

Hello Davood, The first sentence is best, we use the present simple to describe habits or timetabled events. The second sentence using present continuous gives the impression that 9pm is the closing time ONLY tonight and on other days this is different. I hope that helps, Christine

They are both correct. Also: "The mall will be closing at 9 pm tonight." Which one is better may depend on the context.