Preheat your oven to 350°F (175°C).

Line a large baking sheet with parchment paper to prevent sticking.

In a large mixing bowl, use an electric mixer to blend together the granulated sugar, brown sugar, peanut butter, egg, and vanilla extract.

Beat for about 2–3 minutes until the dough is thick, smooth, and fully combined.

Using a heaping tablespoon or cookie scoop, portion out 1 1/4-inch balls of dough.

Roll each ball between your palms until smooth.

(Optional) Roll each ball in a little extra granulated sugar for a slightly crispier exterior.

Place the dough balls on the prepared baking sheet, spacing them about 2 inches apart.

Press down gently with the back of a fork, then rotate and press again to form a classic criss-cross pattern.

To help the fork release the dough, dip the tines in sugar between pressing each cookie.

Bake for about 10 minutes, or until the tops are just turning lightly golden and the cookies are around 3 inches wide.

They will be slightly soft in the middle straight from the oven.

Let the cookies cool on the baking tray for 5 minutes to firm up before transferring to a wire rack to cool completely.

Enjoy warm with a tall glass of cold milk or store them for later.