There are all kinds of adjustable measuring spoons, but I don't know about one that has a wide enough mouth to grate pepper into.

https://www.amazon.com/KitchenArt-51010-Pro-Adjust-A-Tablespoon-Satin/dp/B00117VUO6/ref=sr_1_5?keywords=Adjustable+Measuring+Spoons&qid=1668376448&sr=8-5