With git rebase --interactive <commit> you can squash any number of commits together into a single one. It's an OCD heaven.

And that's all great unless you want to squash commits into the initial commit. That seems impossible to do.

Any way to achieve it?

Moderately related:

In a related question, I managed to come up with a different approach to the need of squashing against the first commit, which is, well, to make it the second one.

If you're interested: git: how to insert a commit as the first, shifting all the others?