Boil 1 litre of water in a large pot. Add a pinch of salt and 200 grams of spaghetti to the boiling water. Cook the spaghetti until it is al dente, which should take about 8-10 minutes.
While the spaghetti is cooking, prepare the pesto sauce. In a mixer, combine 2 cups of fresh basil leaves, 3 cloves of garlic, 50 grams of pine nuts, 1/2 cup of olive oil, and 50 grams of grated Parmesan cheese. Blend until you have a smooth paste.
Drain the cooked spaghetti, reserving some of the pasta water.
In a large pan, add the pesto sauce and cooked spaghetti. Toss well to ensure the spaghetti is well coated with the sauce. If the sauce is too thick, add some of the reserved pasta water.
Serve the spaghetti with a sprinkle of extra Parmesan cheese on top.