Bring a large pot of salted water to boil. Cook the pasta to al dente and save ½ cup of pasta water.
Add basil, pine nuts, garlic, and salt to blender or food processor and blend until thoroughly combined.
With blender or food processor on, slowly add olive oil and lemon juice until well combined. Add the Parmesan and blend for 10 more seconds until just combined.
Add the cooked pasta to a mixing bowl. Add the pesto and ¼ cup of reserved pasta water, tossing to combine. Add more water if still too thick. Top with some Parmesan and fresh basil.
Notes
Use freshly grated Parmesan to finish the sauce. Never buy pre-shredded Parmesan cheese as it contains wood pulp. Blocks of Parmesan cheese are also cheaper.
Use freshly squeezed lemon juice as it tastes better and is cheaper. No store-bought bottle.
Make sure the water you are cooking the pasta in is salted as some of the flavor comes from it.
Cook the pasta until just al dente as the pasta will cook more when tossing in sauce.
Don't heat your pesto as it takes away from some of the aroma/flavor. Just add to the hot pasta.