Bring a large pot of salted water to a boil. Add the spaghetti and cook as the label directs.
Bring the wine, garlic and lemon zest to a simmer in a large skillet over medium-high heat. Gradually whisk in the butter, then the olive oil, until thickened; add 1 teaspoon salt, and pepper to taste. Add the escarole and cook until wilted, about 3 minutes. Add the snap peas and cook until tender, 2 to 3 minutes. Discard the garlic and lemon zest.
Reserve 1/4 cup cooking water, then drain the spaghetti and add to the skillet. Add 1 to 2 tablespoons cooking water and 1 teaspoon salt; toss, adding more cooking water as needed to loosen. Divide among plates and top with the prosciutto, parsley and pecorino.