Because you are linking the two adjectives with and, the most applies to both and you have ended up with most easiest, which is incorrect. "The most incredible and easy path" is correct. While "most easy" is awkward, because it's combined by and with "incredible," it's not only acceptable but the only acceptable expression.
Because most easy is awkward to the point of being wrong, if you were to reverse the order of the adjectives you would need to move most as well:
The easiest and most incredible path
To use easiest and keep incredible first, you need to eliminate the and so that the applicability of most is restricted:
The most incredible, easiest path
Any other adjectives, where they easily form superlatives, must fit the same pattern:
The most incredible, simplest, easiest path
The most incredible and simple, easiest path
Where an adjective doesn't form a superlative with -est, you have a choice:
The most incredible, magical, simplest path
The most incredible and magical, simplest path
The most incredible, magical and simple path
Of these, the first is probably to be preferred.