Preheat your oven to 350°F (175°C) and line a baking sheet with parchment paper or a silicone baking mat.

In a large mixing bowl, combine the peanut butter, granulated sugar, and brown sugar. Mix until smooth and creamy.

Add the egg, vanilla extract, baking soda, and salt to the bowl. Stir until all the ingredients are fully incorporated and the dough is well mixed.

Using a tablespoon or small cookie scoop, portion the dough into 1-inch balls and place them on the prepared baking sheet, spacing them about 2 inches apart.

Use a fork to gently flatten each dough ball, creating a crisscross pattern on the top.

Bake in the preheated oven for 8-10 minutes, or until the edges are lightly golden. The cookies will still be soft but will firm up as they cool.

Remove the baking sheet from the oven and allow the cookies to cool on the sheet for 5 minutes before transferring them to a wire rack to cool completely.