kinda looks like a D spin?
but threads. i've sort of learned to cork 7. i was once told to jump, start spinning, and reach your left hand back to grab your right foot (for spinning left). then it's just a matter of practicing and getting the motion down and stomping. like someone else says, at some point a cork 7 turns into more like a 180 to misty 5 for me.
on a side note, if you're learning new tricks, try for a flat 5. it's really easy. my friend taught me by having me spin a 540 and pick up my legs. it's really easy and super fun to add cool grabs like truck drivers and bow/arrow. just jump, start spinning, and at about 180 or so, suck up your knees and go inverted.