Cook the whole wheat pasta according to package instructions until al dente. Drain and set aside, reserving 1/2 cup of the pasta water.

In a large skillet, heat the olive oil over medium heat. Add the minced garlic and sauté for about 1 minute until fragrant.

Add the fresh spinach to the skillet and cook until wilted, about 3-4 minutes.

Season the salmon fillets with salt, pepper, and lemon zest. Push the spinach to the side of the skillet and add the salmon to the pan. Cook for about 4-5 minutes on each side, or until the salmon is cooked through and flakes easily with a fork.

Remove the salmon from the skillet and flake it into large pieces.

Add the cooked pasta to the skillet with the spinach. Pour in the reserved pasta water, lemon juice, and red pepper flakes (if using). Toss to combine and heat through.

Gently fold in the flaked salmon and sprinkle with Parmesan cheese. Adjust seasoning with salt and pepper as needed.

Serve warm, garnished with fresh parsley if desired.