(Note: Since you can only earn this achievement with the Child, he will be the only suggested character.)
To earn it, use the Child for Level M-4 and follow the crumbling tiles, jumping only once. However. this may be difficult since the structure of the level is pretty awkward. One tip is to jump when you're near the end and hover over the level, as the Child can stay in the air for longer.
Another tip is to use the tiles near corners to completely stop your movement, thus decreasing your speed and increasing your maneuverability. Increased maneuverability will let you reach other platforms more easily.
One thing to know is that there is not one set and stone route you need to use. There's probably more than 5 ways to get this achievement, though some are easier than others.
Using any other character will result in not earning the achievement, even though you may have done the level in only one jump. This achievement was once possible to do with the Pastafarian without the revamp, but it didn't give you the achievement. Now, after the revamp, it's not longer possible.