Pasta with Butternut Squash, Spinach & Mushrooms

Ingredients:
Fettuccine pasta (a mixture of whole wheat, white & spinach is pretty)
1/2 cup (1 stick) butter, divided
3 cups 1/2-inch cubes butternut squash (from 1-pound squash)
8 ounces fresh shiitake mushrooms, stemmed, caps sliced
1 1/2 tablespoons chopped fresh sage
1 5- to 6-ounce bag baby spinach
3/4 cup grated Parmesan cheese, divided

Preparation:
Cook pasta in large pot of boiling salted water until tender but still firm to bite, stirring occasionally. Drain.
Meanwhile, melt 1/4 cup butter in large skillet over medium-high heat.
Add squash and cook until almost tender, stirring often, about 6 minutes.
Add mushrooms, sage, and remaining 1/4 cup butter; sauté until mushrooms are soft and squash is tender, about 8 minutes.
Add spinach; stir until wilted, about 2 minutes. Stir in 1/2 cup cheese. Season with salt and pepper.
Add pasta to sauce in skillet.
Toss to coat, adding pasta cooking liquid by 1/4 cupfuls if dry. Sprinkle with 1/4 cup cheese.