Boil a large pot of water and gently score the top of each tomato. Once the water is boiling, carefully drop the tomatoes into the water and blanch for 1-2 minutes. Scoop the tomatoes out of the water with a slotted spoon and place in a large bowl of ice water. Once the tomatoes are cool, peel off the skins—they should slip right off. Chop the tomatoes and set aside.
Place a large pot over medium heat. Melt the butter in the pot and brown the sausage, breaking it apart with your spoon. Add the onions and garlic then saute another 5 minutes to soften the onions.
Add in the tomatoes, chopped basil, wine, tomato paste, 1 teaspoon salt, and 1/2 teaspoon pepper. Bring to a boil, then cover, lower the heat and simmer for 1 hour.
Remove the lid and simmer another 15-20 minutes. Meanwhile, cook the pasta according to the package instructions. Drain the pasta and serve with a hearty amount of the warm ragu.