Bring a large pot of salted water to a boil. Add the pasta and cook according to package directions until al dente, about 12 minutes. Before draining, reserve ½ cup of the pasta water and set aside. Drain the pasta.

Meanwhile, heat the olive oil in a large skillet over medium heat. Add the garlic and sauté for 30 seconds, until fragrant. Add the mushrooms and cook for 8-10 minutes, stirring occasionally, until they are tender and golden brown. As they cook, they will release liquid, continue sautéing until the liquid has evaporated.

Add the spinach and cook for 1-2 minutes, stirring occasionally, until just wilted. Add the cooked pasta and half of the reserved pasta water. Remove from the heat.

Stir in the grated parmesan cheese, adding more reserved pasta water as needed to create a silky, glossy sauce that coats the pasta evenly.

Serve immediately, topped with more grated parmesan cheese and freshly cracked black pepper, if desired.