Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a bowl, mix the peanut butter, granulated sugar, and brown sugar until smooth.
Add the egg and mix until fully incorporated.
In a separate bowl, whisk together the all-purpose flour, baking soda, and salt.
Gradually add the dry ingredients to the peanut butter mixture, stirring until just combined.
Roll the dough into 1-inch balls and place them 2 inches apart on the prepared baking sheet.
Use a fork to gently press down on each ball, creating a crisscross pattern.
Bake for 10 minutes or until the edges are slightly crisp and the cookies are golden brown.
Remove from the oven and let cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely.