This is a good move to really feel all of those core muscles.
Start with feet flat, knees bent in a normal supine crunch position. Bring the hands up by the cheeks in a boxing position with the elbows in.
Circle slow and wide all the way around. Start by going one direction for a 4 count and reverse after 4 reps around. Repeat based on the level of your class.
A good combo with these could be
Repeat
Always remind to keep the abs and glutes tight and to maintain the initial spine angle without pulling on the head.