Preheat Oven: Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
Mix Ingredients: Take a bow;, combine peanut butter, erythritol, egg, baking soda, vanilla, and salt (if using). Mix until a smooth dough forms.
Scoop Dough: With the help of tablespoon, scoop small balls of dough and place them on the prepared baking sheet, about 2 inches apart.
Shape Cookies: Flatten each ball with a fork, creating a criss-cross pattern on top.
Bake: Bake for 10–12 minutes, until the edges are golden.
Cool: Let cookies to rest on the sheet for 5–10 minutes before transferring to a cooling rack.
Serve: Enjoy warm or store in an airtight container for later.