Combine peanut butter, granulated sugar, brown sugar, egg, and vanilla extract in a bowl; mix until homogeneous.

Preheat the air fryer to 325°F (165°C).

Roll the dough into 1-inch balls, approximately 25 grams each.

Place dough balls in the air fryer basket, ensuring at least 1 inch of space between each for air circulation.

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

Cook at 325°F (165°C) for 8 to 10 minutes until the edges are firm and slightly golden.

Cool inside the basket for 5 minutes to allow the structure to set before moving to a wire rack.