Preheat oven to 180C/Gas 4.
1) Cook the lasagne noodles in plenty of boiling salted water until pliable and barely tender, about 10 minutes. Stir with a wooden spoon to prevent sticking.
2) Drain the noodles thoroughly and coat with olive oil to keep them moist and easy to work with.
3) Coat a large skillet with olive oil, add beef and sausage and brown until no longer pink, about 10 minutes. Season with salt and pepper.
4) In a food processor, combine the onion, carrots, celery, garlic, basil, parsley, and oregano. Process until pureed, add to the pan with the minced meat and stir to combine. Stir in the flour. Add the wine and cook until it has reduced by half. Stir in the tomatoes and add the double cream and the cinnamon.
5) In a mixing bowl, combine ricotta and the Parmesan. Stir in the eggs and season with salt and pepper.
6) To assemble the lasagne: Coat the bottom of a deep 30 by 20-cm pan with olive oil. Arrange 4 noodles lengthwise in a slightly overlapping layer on the sauce. Then, line each end of the pan with a lasagne noodle. This forms a collar that holds in the corners.
7) Dollop 1/2 of the ricotta mixture over the pasta, spread to the edges with a spatula. Spread 1/2 of the meat mixture over the ricotta. Sprinkle 1/2 of the mozzarella on top of the ricotta. Top with a ladle full of sauce, spread evenly.
8) Repeat with the next layer of noodles, ricotta, sauce, and cheeses. Top last layer with noodles, sauce, shredded mozzarella and Parmesan. Tap the pan to force out air bubbles. Bake for 1 hour.
9) Remove from oven. Let lasagna rest for 30 minutes so the noodles will settle and cut easily. Cut into 5-cm squares and serve.