In a large, high-sided skillet, melt the butter (3 tablespoons) over medium heat. Add the prosciutto (2 ounces), onion (1), and red pepper flakes (1 pinch) and cook until the onions are very soft about 10 minutes. Turn up the heat to medium-high and stir in the garlic (3 cloves). Cook, stirring constantly for 30-45 seconds. Add tomato paste (2 tablespoons) and sun-dried tomatoes (3 tablespoons) and continue to cook, stirring constantly, for one minute. Pour 1/4 cup of wine into the skillet and cook, stirring often, until all the liquid has evaporated, 1 to 2 minutes.
Meanwhile, bring 4 quarts of water to a boil. Add 1 tablespoon of salt. Cook the Cavatappi (1 pound) until al dente, according to package instructions. Before draining, reserve 1/2 cup of pasta water. Drain Cavatappi well then return it back to the cooking pot.
Add 2 cups of crushed tomatoes, salt (1 1/2 teaspoons), pepper (1/2 teaspoons), and a pinch of sugar. Bring to a boil, then reduce heat to a simmer. Cover partially, and continue to simmer, stirring occasionally, until the sauce is thickened, (a spoon dragged through the sauce will leave a trail) about 15 minutes. Add cream (1/2 cup), basil (1/4 cup), the remaining 2 tablespoons of crushed tomatoes, and the remaining 2 tablespoons of wine to thicken the sauce. Stir to combine. Adjust seasoning.
Toss Cavatappi with sauce. Adjust the consistency with cooking water as needed. Serve immediately.