Preheat the oven to 350°F and line a baking sheet with parchment paper.

Add the peanut butter and brown sugar to a large mixing bowl. Mix until creamy and well combined.

Add the melted plant-based butter, vanilla extract, and room-temperature plant milk. Mix until combined.

Add the flour and baking soda. Stir until everything comes together and a cookie dough forms. If the dough feels too dry, add plant milk 1 teaspoon at a time. If it feels too sticky, add flour 1 tablespoon at a time.

Scoop the cookie dough and roll it into balls. Place them on the prepared baking sheet, leaving a little space between each cookie.

Pour the white sugar into a small bowl. Dip a fork into the sugar, then gently press it into the top of each cookie. Turn the fork and press again in the opposite direction to make the classic crisscross design. Dip the fork back into the sugar as needed.

Bake for 11 minutes.

Let the cookies cool on the baking sheet for 10 minutes before transferring them to a wire rack to finish cooling.