This is tougher than it sounds, at least in the USA. This 2018 law-review article fully works two examples for Pastafarians, focusing on Holy Headgear (pasta strainers, colanders, or salad spinners, worn as hats) and Friday. Their opinion is fairly nuanced because employers are traditionally given a wide range of options for proffering labor to employees without infringing on employee expression. They conclude that the main issue with Pastafarian claims isn't anything to do with the sincerity of religious belief, but the specific nature of asking to never work another Friday again. Fridays are too much of a request, but Holy Headgear is probably fine. The prophet wrote some commentary on this article:

Talking to Mr. Dowdy a bit, I don’t know his exact opinion on whether Pastafarians should be granted allowances to dress as Pirates and take every Friday off of work… I believe the larger point of his article is that courts should not be deciding what is and what is not a True religion and it’s not their place to maintain a list of protected religious activities that are deemed acceptable in the workplace.

Flipping things around, employers have been hesitant to embrace or endorse my Pastafarianism even when I enthusiastically point out e.g. that I can work during the winter solstice. They know that it would lead to requests for religious respect. BTW, somebody's surely gonna be a little snot and say something like "but Pastafarianism isn't a real religion, it's a parody." First, they're missing the point: employers think religious complaints about AI are bullshit, just like they think Pastafarianism is bullshit, which is why they're not predisposed to honor such complaints. Second, they're missing the point: I don't need their permission to eat noodles every Friday, but I do need an employer's permission to not be scheduled to work.