Let's say I have a relatively large commit that contains an addition that I want to do again, but in a modified variant. Is there a way to re-apply the diff to the branch which already contains this commit?

The idea is to apply this commit over and over again, so it would serve as a template for similar additions. One way I see to do that is to keep creating branches from the point where this commit is not applied, than merge trivially. But is there a better way?