Begin by cooking the thin rice noodles according to the package instructions, then drain and rinse with cold water to stop the cooking process.

In a small bowl, combine peanut butter, hoisin sauce, lime juice, soy sauce, and water. Whisk until smooth and adjust consistency as needed.

In a large mixing bowl, add cucumber, purple cabbage, carrot, and red pepper. Toss to combine.

Add the cooled rice noodles to the bowl with vegetables. Gently fold in cilantro and mint.

Drizzle the dressing over the salad and toss until fully coated.

Sprinkle chopped peanuts on top if desired. Serve immediately.