Prepare the rice noodles according to the package instructions until they are tender but still have a slight bite (al dente). Drain the noodles, rinse them under cold water to prevent sticking, and set them aside.

In a small bowl, whisk together the soy sauce, oyster sauce, fish sauce, and brown sugar until the sugar has completely dissolved. Set this savory sauce mixture aside for later.

Heat the vegetable oil in a large wok or skillet over medium-high heat. Add the minced garlic and sliced Thai chilies, stir-frying for about 30 seconds until highly fragrant.

Add the prawns to the wok and cook for 2 to 3 minutes, flipping once, until they turn pink and opaque. Use a slotted spoon to remove the prawns from the wok and set them aside on a plate.

In the same wok, add the sliced red bell pepper and stir-fry for 2 minutes until it begins to soften. Return the cooked prawns to the pan along with the prepared rice noodles.

Pour the prepared sauce over the noodles and prawns. Toss everything together continuously for 2 to 3 minutes until the noodles absorb the sauce and are heated through.

Stir in the bean sprouts and green onions, cooking for an additional 1 minute until the vegetables are just slightly softened but still crisp. Remove the wok from the heat.

Divide the spicy Thai prawn noodles among four serving bowls. Garnish generously with crushed peanuts and fresh cilantro, and serve immediately with lime wedges on the side for squeezing.