It's not PERFECT, but here's how I did this:
I created a star
Convert it to curves
Use your Shape Tool (edit nodes tool)
Select all nodes and convert lines to curves (on the Shape Tool menu bar)
Then select only the inner nodes
Hit rotate (again, on the Shape Tool menu) and rotate them a little
That woudl be fine, but I didn't like how the inner nodes' handles were pointed, so:
With the inner nodes selected still, I hit convert curves to lines (you may need to reverse the curve for this to work the way you want it) then convert lines to curves right away
Then I rotated the inner nodes slightly again.
You could acheive the same result by working with the outer nodes if you'd like.
