Bring a large pot of water to a boil, add a handful of salt. Cook the pasta for 2 minutes less than the instructions on the box.
In a large sauté pan, cook the chopped onion over low heat until it starts to sweat. Add the garlic and bacon pieces, cooking until the bacon is crispy on the edges. Set aside and DON’T DRAIN THE GREASE.
In a large bowl, combine Parmesan, half & half and eggs.
Drain the pasta when it’s ready, reserving a cup or so of cooking liquid (dunk a coffee cup into the pot and set aside.)
Pour the pasta into the pan with all the bacon, onions and garlic and use tongs to move the pasta until it’s coated. (Or vice versa, adding the bacon to the large pasta pot if needed.)
Add the Parmesan mixture to the pasta and stir to combine.
Crack fresh black pepper (and basil if using) over the top and serve immediately.