A more formal name for the name "Pepper"?

I really want to name my daughter Pepper. Her sister is Olive and we're sticking to a theme. I really like it and am not interested in hearing any opinions against it. What I do need help with is coming up with a more formal name so that Pepper could be an easy nickname (so if she's not a quirky as me, she still has options). I haven't found any names that start with "Pep" besides Pepita and Pepelina and the like but I don't like those. Maybe it can be extracted from the middle or end of a name, like my name is Trish but my formal name is Patricia. Get it? I hope someone has a good idea! Thanks!