Bring a large pot of salted water to a boil. Add the spaghetti or linguine and cook according to the package instructions until al dente. Before draining, reserve about ½ cup of the pasta cooking water.
Optional: In a large skillet, melt the butter over medium heat. Add the sliced mushrooms and cook until they are tender and browned, about 5-7 minutes.
Add the minced garlic and sauté for about 1 minute until fragrant.
Pouring in the white wine. Let it simmer for a minute until reduced by half.
Combine the miso paste with a couple of tablespoons of pasta water to form a smooth paste and add to the skillet.
Add the pouring cream and stir to combine. Simmer the sauce for 2-3 minutes, allowing it to thicken slightly.
Add the Parmesan and stir in salt and pepper to taste.
Remove the skillet from the heat. Add the cooked and drained spaghetti or linguine and toss to coat evenly, adding a little pasta water a tablespoon at a time until the pasta is moist and juicy.
Serve immediately, topped with optional furikake/sesame seeds.