Prepare the fresh vegetables: Start by preparing all the vegetables so everything is ready to assemble. Thinly slice the carrot, bell pepper, red cabbage, and onions into delicate strips. Thin slices help mimic the crisp filling typically found in spring rolls. Remove the thick stems from the parsley and roughly chop the leaves. Set everything aside while you prepare the noodles and sauce.
Cook the rice noodles: Bring a pot of water to a boil and cook the rice noodles according to the package instructions until they are al dente, tender but still slightly firm. Properly cooked spring roll noodles should be soft but not mushy. Drain the noodles and set them aside.
Make the creamy peanut sauce: In a medium bowl, combine the peanut butter, brown sugar (or maple syrup), tamari or soy sauce, fresh lime juice, minced garlic, and grated ginger. Stir until the mixture begins to smooth out.
Thin the Peanut Sauce: Heat about ¼ cup of water until it is just below boiling. Gradually whisk the hot water into the mixture a little at a time until the peanut sauce becomes smooth and pourable. Add more warm water if you prefer a thinner sauce for drizzling over your spring roll bowls.
Assemble the spring roll bowls: Divide the cooked rice noodles evenly among serving bowls. Arrange the sliced vegetables over the noodles, creating a colorful mix of cabbage, carrots, peppers, and onions.
Add the sauce and toppings: Generously drizzle the prepared peanut sauce over each spring roll bowl so it coats both the noodles and vegetables. Finish with your favorite toppings such as fresh herbs, chopped peanuts, bean sprouts, or toasted sesame seeds for extra flavor and texture.