Preheat oven to 350 degrees F and line a baking sheet with parchment paper
Add the peanut butter, brown sugar, egg, vanilla extract, and salt to a medium-sized bowl. Stir all ingredients together with a spatula until a dough forms.
Using a cookie scoop, scoop out dough and place dough on the prepared baking sheet, spacing them about 2 inches apart. Press down on top of the dough with a fork to flatten the dough and to form a crosshatch pattern.
Bake cookies for about 15-18 minutes, or until brown. Remove them from the oven and let them cool for about 5 minutes.
Optional step - Melt the chocolate chips in the microwave, stirring in increments, until melted. Dunk one side of the cooled cookies into the melted chocolate and place back on the baking sheet. Once all cookies are dunked in chocolate, add flaked sea salt on top and transfer the sheet to the fridge for about 10, or until the chocolate has hardened.