Roast pine nuts without oil in a pan and let cool off afterwards.
Crush pine nuts evenly in a mixer. Then add tomatoes, olive oil, yeast flakes and salt and mix until a smooth consistency. Add rosemary and basil and mix again.
Spaghetti or Farfalle fit perfectly with a pesto, because they soak up oily sauces best. Generously salt the water of the pasta when cooking. Before serving mix together half of the pesto already with the pasta.