Prepare pasta according to package instructions. Drain and toss in a little olive oil.
Toast the pine nuts in a dry skillet over low heat for a few minutes until golden brown.
Add basil, garlic, lemon juice, parmesan cheese and salt to a food processor and blend until well combined.
Stream in the olive oil, a tablespoon at a time, blending in between until emulsified and smooth.
Add the sour cream to the pesto and mix well.
Add the pasta to a large bowl, add the sauce and mix well.
Add the tomatoes and mix well.
Top with extra parmesan, toasted pine nuts and a few extra basil leaves.