Preheat the oven to 350 degrees Fahrenheit. Line a baking sheet with a silicone liner or parchment paper.
Place the peanut butter, sugar and egg in the bowl of a stand mixer. Beat on medium speed with the paddle attachment until well combine.
Make small balls (about 1 1/2 inches) with your hands and evenly space apart on the baking sheet. Using the back of a fork make a criss- cross pattern on each cookie.
Bake for 10 minutes. Let the cookies cool for a few minutes before enjoying.