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

Stir the peanut butter, sugar, and egg together in a bowl until a thick dough forms.

Roll the dough into walnut-sized balls and space them out on the sheet.

Flatten each ball with a fork in a crisscross pattern.

Bake for 10 to 12 minutes, until the edges are set but the centers still look soft.

Cool on pan 5 minutes to firm before moving.