The amount of butter to use depends on how much ravioli you are making. I made one big package of fresh spinach ravioli and used about one stick of butter. Top the ravioli with freshly grated Parmigiano-Reggiano for added flavor and a little saltiness.
While the ravioli is cooking, melt the butter in a small saucepan. When the butter turns light brown, after about three minutes, take the pan off the heat and toss in a handful of pine nuts. Add salt and pepper to taste. Pour the sauce over the cooked ravioli and top with cheese.