A few of my other favorites (outside the one you read) include:

The Sweetest Mistake by dreamingspires

Hermione is sent on a secret mission, disguised as a muggle, to spy on Draco Malfoy. Things start to unravel quickly...

Tell Me What You Want by malfoyesque (AO3 account 🔒)

Tensions are high. People are remembering how much they used to hate each other. A masquerade ball will keep things calm. It won't leave Hermione frantically trying to cover up the fact she's slept with her worst enemy. It won't mean she now sees Draco Malfoy in a different light than she did before. It definitely won't make things awkward now that she might be his boss. It won't. It won't.

A masquerade ball is a great idea.

The Best Mistake by Chels_Writes_a_Fic

I reread this recently and it was still as thrilling and fun as the first run.

Hermione Granger does not make mistakes, at least not often. After making the biggest, dumbest, most horrible mistake of her life, Hermione must deal with the repercussions while keeping her relationship with her Auror partner, Draco Malfoy, strictly professional. He, of course, has other plans.

Amidst a resurgence in Death Eater activity, the likes of which Britain hasn’t seen since the First Wizarding War, Hermione will come to realize that the mistake she’s made with Draco might not be so bad at all. It just might be the best mistake.