1. Preheat oven to 350° F.

2. Heat 2 tablespoons extra-virgin olive oil in a large skillet or saucepan over high heat. Add the sausages and cook, stirring, until browned, 4 to 5 minutes. Add the onions, 1/4 teaspoon salt and the black pepper. Cook, stirring occasionally, until the onions are just soft, about 4 minutes. Add the basil and garlic, and cook, stirring, for 2 minutes. Add the vodka and tomatoes, reduce the heat to medium-low, and simmer, uncovered, stirring occasionally, for 40 minutes. Add the Essence and heavy cream, stir to mix, and simmer for 5 minutes. Remove from the heat.

3. To cook the pasta, combine 4 quarts water, the olive oil, and the remaining teaspoon salt in a large pot over high heat. Bring to a boil, add the pasta, and cook until al dente, 12 to 14 minutes. Remove from the heat and drain well. Combine half of the ricotta cheese and half the Parmigiano-Reggiano with the remaining 2 tablespoons extra-virgin olive oil in a large mixing bowl. Add the pasta and toss to coat evenly. Add the sausage mixture and mix well. Add the remaining ricotta cheese and the remaining Parmigiano-Reggiano and mix well.