Prep: Preheat oven to 350°F and line a baking sheet with parchment paper for easy cleanup.
Mix: In a large mixing bowl, add the peanut butter, brown sugar and egg and stir well to incorporate. Let the dough stand for at least 10 minutes on the countertop.
Bake: Use a tablespoon measure to scoop out balls of dough onto the baking sheet, leaving a couple inches in between each, and then use the back of a large fork to gently press down each cookie, creating a crisscross pattern. Sprinkle the cookies with sea salt (if using) and then bake for 12-13 minutes or just until the edges start to brown. Once out of the oven, let the cookies set on the baking sheet for another five minutes.
Enjoy: Carefully transfer the cookies to a wire rack to cool, and enjoy! Cookies can be stored in the fridge for up to five days.
Notes
Peanut butter:Salted, creamy no-stir peanut butter work best for this recipe. If you use natural peanut butter (the kind with oil separated on top when you first open it), make sure to stir it really well first in order to incorporate all the oil. Crunchy peanut butter works too if you prefer crunchier cookies! And if the peanut butter you use doesn't have added salt, you'll want to make sure to sprinkle the optional sea salt on top to balance out the sweetness.