Boil the noodles and cook al dente according to the package directions.
While waiting for the water to boil, prepare the sauce. In a small bowl stir together the brown sugar, soy sauce and sriracha.
In a large skillet melt 2 tablespoons of butter over medium-low heat. Add the red pepper to the butter as it melts. Whisk an egg in a bowl and then add to the melted butter. Stir gently and cook through. Once the egg is done cooking; turn off the heat.
When the noodles are tender, drain the water and then add them to the skillet with the cooked egg. Then add the prepared brown sugar/sauce. Turn the heat down low to evaporate excess moisture and stir until everything is coated well with the sauce. Sprinkle the sliced green and cilantro leaves on top and serve immediately.