Wash, clean, core the pumpkin and cut into small cubes. Fry the pancetta and pumpkin with olive oil in a deep, non-stick pan and cook for 5 minutes over a medium heat, turning occasionally.
Put the cream in a small saucepan and bring to the boil. Whisk the eggs in a bowl and stir in the boiling cream with a whisk. Then return to the saucepan and heat while stirring until the sauce thickens, then remove immediately from the heat and mix with the pumpkin and bacon mixture.
Cook the spaghetti in plenty of boiling salted water until al dente. Drain and drain. Clean the spring onions and cut diagonally into fine rings. Arrange the spaghetti with the pumpkin carbonara on plates and serve sprinkled with spring onions. Sprinkle with freshly grated Grana Padano or Parmigiano Reggiano as needed.