Drop the spaghetti in a large pan of boiling salted water, stir occasionally for 10-12 minutes until ‘al dente’ (tender but still firm to the bite).
Meanwhile, heat the butter in a frying pan. Add the shallot and garlic and sauté for 2-3 minutes until softened but not coloured. Stir in the pancetta or bacon and cook for another 2-3 minutes until sizzling and lightly golden.
Break the eggs into a bowl and add the cream, two-thirds of the Aged Cheddar and the parsley. Season to taste and lightly whisk to combine.
Drain the spaghetti and return back to the hot pan. Quickly pour in the egg mixture and toss well to combine with the crispy bacon mixture; the heat from the spaghetti will cook the eggs.
To serve, divide the pasta carbonara among wide-rimmed bowls and scatter the remaining Aged Cheddar on top with the parsley.