There are a few core exercises you can do. The powerlifting movements (squat, deadlift) work the core already. Also, every movement you do is going to require a bit of core activation so you also have that. Besides that I recommend planks, front squats, weighted carries, sled push, holds, etc. 

Other sites also have their own opinion on this question so below are a few other answers.

Here’s a video from Gaglione Strength for core exercises: 

According to Barbend a few core exercises to do are the Ab Wheel, Weighted Planks, and the Standing Cable Crunch (they also tell you how to do the exercise). 

Now, T-nation had a few different answers to this question. 

For example, they mentioned anti-extension exercises like planks, body-saw, TRX fallouts, walkouts, etc. 

They mentioned anti-lateral flexion exercises like side plank variations, single arm carries, and suitcase deadlifts. 

They also had a few other helpful exercises to do on their site. 

As you can see there are a few movements you can do to strengthen your core or powerlifting.