Preheat oven to 350°F (175°C).

Line a baking sheet with parchment paper or a silicone baking mat.

In a medium bowl, mix sugar, peanut butter, and egg until fully combined.

Roll the dough into 1-inch balls and place on the baking sheet.

Flatten each ball using a fork to create a criss-cross pattern.

Bake for 10–12 minutes until edges are set.

Let cookies cool slightly before transferring to a wire rack.

These 3 ingredient peanut butter cookies bake quickly, so keep an eye on them to avoid overbaking.