Preheat your oven to 350°F (175°C). Line two baking sheets with parchment paper.
In a large mixing bowl, combine the peanut butter and granulated sugar. Mix until smooth and creamy.
Add the egg, baking soda, vanilla extract, and salt to the peanut butter mixture. Stir until all ingredients are fully incorporated and the dough is smooth.
Using a tablespoon or cookie scoop, scoop out dough portions and roll them into balls about 1 inch in diameter.
Place the dough balls onto the prepared baking sheets, spacing them about 2 inches apart.
Flatten each dough ball gently with the back of a fork, creating a crisscross pattern.
Bake in the preheated oven for 8 to 10 minutes, or until the edges are set but the centers still look slightly soft.
Remove the cookies from the oven and allow them to cool on the baking sheets for 5 minutes before transferring them to a wire rack to cool completely.