Cook the spaghetti according to the packet instructions.
A couple of minutes before the pasta is cooked, add the frozen peas and boil for a further few minutes.
Drain the cashews and add all the carbonara sauce ingredients to a blender and blend until smooth, 2 minutes.
Drain the pasta and place back into the pan you boiled it in, adding in the spinach and stiring until wilted.
Pour over the sauce, stir through, then serve.