Place the prosciutto in a wide pot and turn the heat to medium. Cook for 5 minutes until the fat begins to render.
Add the beef and sausage and cook for 12-15 minutes, breaking it up with a wooden spoon as it cooks, until cooked through. Transfer to a paper towel-lined plate. Remove all but 1 tablespoon fat from the pot.
Cook the mushrooms:
Add the mushrooms to the pot and cook, stirring often, for 10 minutes until crisp and golden brown. Season with salt and pepper.
Cook the aromatics:
If the pot is dry, add 1 tablespoon olive oil to the mushrooms. Add the diced onion and celery to the mushrooms and cook for 6-7 minutes. Season with salt and pepper.
Add the garlic and cook for 1 minute until fragrant. Add the onion jam and toss to coat.
Simmer the ragu:
Return the cooked meat to the pot. Add the whole peeled tomatoes and 2 cups of water or beef stock. Taste and season with salt, pepper, and crushed red pepper. Bring to a boil. Reduce heat and simmer for 1 hour. Add more water or beef stock if the liquid evaporates too quickly. Once thick, turn off the heat and stir in the heavy cream. Keep warm.
Make the pasta:
Once the ragu has finished cooking, bring a large pot of salted water to a boil. Cook the pasta until al dente. Remove 1/4 cup of pasta cooking water and then drain the pasta.
Turn the heat on the ragu to medium-high. Once bubbly, add the pasta cooking water and stir to combine. Add the cooked pasta and toss for 1 minute until glossy. Turn off the heat.
To serve:
Divide the pasta and ragu between bowls. Serve with basil, parmesan, and extra virgin olive oil if you like!