Making a circle batman cape, which method will work best?

[barefootbird]

I happen to have some nice thick black cotton/polly-cotton fabric, standard width. Do I:

A: just cut a huge semi-circle using the whole width of the fabric, make a head-hole, make bat man style inverted scalloped edge around the bottom which is finished with a bias binding (visible on the inside only).

B: make a straight sided cape with the same finish along the bottom as above.

DS2 is only 5 so the cape doesn't have to be huge. I was going to make a Velcro neck strap. I had wondered about making a small hood as well but I may run out of time.

Any other costume making tips would also be gratefully appreciated!