Preheat the oven to 350ºF and prepare a large baking sheet by lining it with parchment paper or a silicone baking mat. Set aside.

In a mixing bowl, combine peanut butter, sugar, and egg using either an electric mixer or a spatula. Blend the mixture thoroughly until it becomes creamy and smooth.

Using about 1 tablespoon of cookie dough per cookie, form the dough into balls and place them onto the prepared baking sheet, about 2 inches apart. Flatten each ball with the back of a fork, creating a criss-cross pattern. *If desired, you can roll the dough balls in granulated sugar before adding the criss-cross pattern.

Bake for 8-10 minutes or until the edges turn slightly golden and they are a little puffy. Remove from the oven and allow them to cool on the baking sheet.