Preheat your oven to 350°F (175°C).

In a mixing bowl, whisk together the flour, baking soda, and salt.

In another bowl, beat together the peanut butter, brown sugar, and granulated sugar until smooth.

Add the egg and vanilla extract to the peanut butter mixture and mix until combined.

Gradually add the dry ingredients to the wet ingredients, mixing until just combined.

Scoop tablespoon-sized balls of dough onto a baking sheet lined with parchment paper.

Flatten each ball slightly with a fork, creating a crisscross pattern on top.

Bake in the preheated oven for 8-10 minutes, or until the edges are lightly golden.

Remove from the oven and let cool on the baking sheet for a few minutes before transferring to a wire rack.