Combine the oil and butter with all of the sausages in a large heavy bottom pot on medium low heat, stirring often, for about 10 minutes.
Increase heat to medium-high. Add the onions, carrots and celery stirring frequently, cook until vegetables are softened and the onions are translucent.
Drain any excess fat and add wine to reduce the mixture until almost dry. Stir in the tomato paste and cook for 3 minutes, until lightly camelized. Season the sauce with salt, pepper, nutmeg, cinnamon and allspice.
Add the stock, bring the sauce to a boil, lower heat to low, and simmer uncovered for 2 hours, or until the mixture has reduced and the flavors have concentrated. Add more stock if necessary to avoid burning the bottom of the pot.
Stir in the cream just prior to serving and return the sauce to a simmer. Do not allow sauce to boil. Adjust seasoning with salt and pepper.
Layer a 9 x 13 pan sprayed with cooking spray with one smoothed out layer of Bolognese, then layer of lasagna noodles, layer of Bolognese and repeat to make 7 - 9 layers.