Cook the pasta in salted water until al dente. Reserve 1/2 cup pasta water, then drain.
Blend the cottage cheese, milk, Parmesan, garlic, Italian seasoning, and black pepper until smooth.
Heat the olive oil in a large skillet over medium-low heat. Add the blended sauce and warm it gently without rapidly boiling.
Add the cooked chicken and spinach. Stir until the chicken is hot and the spinach wilts.
Add the pasta and toss to coat. Use reserved pasta water a little at a time until the sauce is creamy and glossy.
Taste and add salt only if needed. Serve with extra Parmesan or black pepper.