Step 1Bring a large pot of salted water to a boil. In a saute pan over medium heat, toast the pine nuts until golden and fragrant, about 5 to 7 minutes, stirring frequently. Cool and reserve.
Step 2Using a mortar and pestle, pound the garlic cloves and salt until very well combined. Working a little at a time (depending on how big your mortar is), add 1 cup of the pine nuts, basil and Parmigiano-Reggiano and mash the mixture until it's a paste. Remove the mixture to a small bowl. (The basil mixture can also be made in a food processor.)
Step 3Gently stir the olive oil into the basil mixture to form a pesto. This makes about 1 1/4 cups pesto, more than is needed for this recipe.
Step 4Working in batches, place the pasta in the boiling water and cook just until tender, about 3 minutes. Drain and lightly coat the pasta with a drizzle of olive oil so that the noodles do not stick together.
Step 5Divide the warm pasta among bowls or plates. Ladle about one-eighth cup of pesto over each serving and sprinkle with the reserved pine nuts. Serve immediately.