In Star Trek Headcanon: Human Edition, What is the reference about turning a sun into a torus?

Star Trek Headcanon: Human Edition inspired me to go through and watch the entire franchise from beginning to end. I have identified almost every reference in the headcanon except one.

Vulcan Science Academy: This is a species where if you give them two warp cores, they will ask for a third one, immediately plug all three into each other, punch a hole into an alternate universe where humans subscribe to an even more destructive ideological system, fight everyone in it because they’re offended by that, steal their warp cores, plug those together, punch their way back here, then try to turn a nearby sun into a torus because that was what their initial scientific experiment was for and they didn’t want to waste a trip.

Vulcan Science Academy: They did that last week. We have the write-up right here. it’s getting published in about six hundred scientific journals across two hundred different disciplines because of how many established theories their ridiculous little expedition has just called into question. Also, they did turn that sun into a torus, and no one actually knows how.

What is this in reference to? Is this referring to an episode, or a novel, or perhaps part of the animated series?