You have the same two options in Git:
vim file/with/typo.txt
git add file/with/typo.txt
git commit --fixup=abcd1234
git rebase --autosquash -i
For some reason I need to pass --interactive/-i, even if I don't actually want it to be interactive. I am not sure if this is just a bug in my Git version or if this is intended.The git commit step can also be replaced with git-absorb, if you have this installed and abcd1234 was the last time you modified these lines.
The second approach is this:
git rebase -i abcd1234~
# do 's/pick abcd1234/edit abcd1234/' in your editor
vim file/with/typo.txt
git rebase --continue