Clean and wash the pumpkin, remove seeds and cut the flesh into pieces about 1 cm in size. Peel garlic and chop finely. Heat the oil in a large pot. Steam garlic colourlessly while stirring.
Add pumpkin and steam for 1-2 minutes. Heat broth and pour into the pumpkin. Halve the noodles and add to the pot. Cover and simmer for about 8 minutes.
Crumble the cheese, add it to the pot with cream and stir in carefully. Let simmer for another 2 minutes. Season to taste with salt and pepper. Wash basil, shake dry, pluck off leaves and, except for something to garnish, chop roughly and add to the pasta.
Arrange one-pot spaghetti, garnish with basil.