Before you start, preheat oven to high grill. Bring a large pot of salted water to a rolling boil.
Prep onion and garlic. Heat oil in a large pot on medium-high heat. Add onion and garlic and cook for about 3 minutes, until tender. Add pumpkin, Italian spices and salt and cook for 1 minute, until fragrant. Add stock, bring to a simmer. Once simmering, cover, reduce heat to medium and cook for about 15 minutes, until pumpkin is very tender and liquid has reduced. Add a little water if sauce becomes too dry.
Meanwhile, cook pasta in pot of boiling water for 9-10 minutes, until just tender. Drain and return to pot with oil to prevent sticking.
Place bacon in a single layer on an oven tray. Grill for about 5 minutes each side, until golden and crispy. Leave to cool slightly, then roughly chop.
To finish, grate courgette. Remove sauce from heat and roughly mash pumpkin into a thick sauce. Add courgette, spinach, cooked pasta and sour cream to pot and stir to combine. Add a little water, if needed. Season to taste with salt and pepper.
Serve pasta topped with bacon and Parmesan.