In a small blender or food processor, blend together the eggs, basil blended in olive oil (or fresh basil leaves + 15ml olive oil), and 1 tablespoon of grated parmesan. Blend until smooth and creamy. Set aside for later — this mixture will be stirred in at the end to enrich the sauce with a silky, herbal finish.
Place the diced guanciale or pancetta into a cold, dry pan. Turn the heat to medium and cook gently for about 4–5 minutes, allowing the fat to slowly render out. Once it becomes golden and slightly crispy, remove it with a slotted spoon and set aside on a plate.
In the same pan (with rendered fat), add the sausage meat. Break it apart with a spatula into small, coarse pieces. Cook over medium heat for about 6 minutes, until browned and fully cooked through. Remove from the pan and set aside with the pancetta.
Still using the same pan, add the butter and diced onion. Sauté over medium heat for about 30 seconds, then stir in the minced garlic. Cook for 1 minute until fragrant. Add the Issou spice blend (or just chili flakes + paprika) and cook for another minute to toast the spices.
Pour in the white wine and allow it to simmer and reduce by half (about 3–4 minutes). Add the crushed tomatoes and chicken broth. Stir well to combine, then add the thyme sprigs and bay leaves.
Reduce the heat and let the sauce simmer uncovered for 30 minutes, stirring occasionally. After about 15 minutes, remove the thyme and bay leaves. Return the cooked sausage and pancetta to the sauce. Continue simmering to thicken and develop flavor.
Bring a large pot of water to a boil and salt it well (10g salt per liter of water). Cook the rigatoni until just under al dente, following package instructions. Reserve a cup of pasta water, then use a slotted spoon or spider to transfer the pasta directly into the sauce. Do not fully drain the pasta — the residual starchy water helps bind the sauce.
Turn off the heat. Quickly stir in the egg-basil-parmesan mixture. Mix vigorously to create a glossy, emulsified sauce. The residual heat will gently cook the eggs and bind the flavors, similar to a carbonara-style finish.
Taste the pasta and adjust the seasoning with salt and freshly ground black pepper if needed.
Divide the pasta among serving plates. Top generously with the remaining grated parmesan and, optionally, extra basil or black pepper. Serve immediately.