Bring a large pot of salted water to a boil. Add in pasta and cook until al dente.
At the same time, in a large saucepan, heat butter over medium to high heat.
Add in garlic and lemon zest and brown for 1-2 minutes.
Add in flour and parmesan and stir until combined.
Stir in lemon juice and cream and stir.
Adjust salt and pepper and simmer for 2-3 minutes until creamy.
Stir in the pasta, mix well, top with parsley and serve straight away.