Preheat the oven to 350 degrees F and line a baking sheet with parchment paper.

Combine peanut butter, sugar, and the egg in a medium bowl, stirring until smooth. Scoop portions of the cookie dough and roll into a ball. Place on the prepared baking sheet. Cookies will not spread at all.

Make a crosshatch pattern on the top of each dough ball using a fork.

Bake for 10 to 12 minutes. Remove from the oven and let sit on the baking sheet for 2 minutes before transferring to a cooling rack.