Bring a large pot of salted water to a boil. Add the pasta, and return water to a boil. Cook pasta for 8 to 10 minutes, or until al dente; drain well.
In an electric food processor or blender, blend cilantro, garlic, vinegar, Parmesan cheese, cayenne pepper, nuts, and salt. Add 1/4 cup of the olive oil, and blend the pesto. Add more olive oil until the pesto reaches your desired consistency.
Pour pesto in a small saucepan and warm over low heat, stirring constantly, until pesto begins to simmer. Pour over cooked pasta and toss.
