In a large pot, bring salted water to a boil. Add the fettuccine and cook according to package instructions until al dente. Drain and set aside, reserving ½ cup of pasta water.
In a large skillet over medium heat, add olive oil. Once heated, add the minced garlic and sauté for about 1-2 minutes until fragrant, being careful not to burn it.
Lower the heat slightly, then add the heavy cream, lemon zest, and lemon juice to the skillet. Stir until the mixture is smooth and heated through.
Gradually stir in the grated Parmesan cheese until melted and well incorporated into the sauce. If the sauce is too thick, gradually add reserved pasta water until desired consistency is reached.
Add the drained fettuccine to the skillet and toss to coat the pasta evenly with the creamy lemon sauce. Fold in the chopped basil, and season with salt and pepper to taste.
Remove from heat and allow to sit for a minute. Serve immediately, garnished with lemon slices and fresh basil sprigs.
Notes
Adjust the amount of lemon juice to taste for desired tanginess.