Quilter's cache also has double star. There is another I really like, but I don't find it there. It is also based on a 9 patch with 4 peaky/spike units. ( draw a square. mark the centerpoint on the upper edge. Draw lines to that from the 2 lower corners.) there are specialized rulers for this, but you can make this PP pattern on your own.
another way to think about it is to take the friendship star and drag the star points to the outer center of their squares.