Laser cut from parchment paper, no less:
Radial slits around the middle let it bend upward over the folded aluminum joint around the pillar:
Ours claims to be a 10×4-½ inch pan, roughly the diameter at the top and the overall height. Your pan will surely be different: this one is, as the saying goes, old enough to know better.
The SVG image as a GitHub Gist:
Made in anticipation of the next time Mary bakes a special carrot cake with cream cheese frosting for my birthday …