In a large pot filled with salted water, cook noodles according to package’s directions. When finished cooking, drain and place noodles in a large bowl.
While noodles are cooking, whisk all remaining ingredient (aside from toppings) together in a medium saucepan. Place saucepan over medium heat and cook until the sauce starts to thicken. Remove from heat.
Add peanut sauce to bowl with cooked noodles. Toss to coat noodles in sauce.
Serve noodles in individual bowls and top with crushed peanuts, chopped cilantro, and additional red pepper flakes.