Start by spiralizing the zucchinis into noodles and setting them aside.
Heat the olive oil in a medium skillet over medium heat. Season the chicken breasts with salt, pepper, and garlic powder. Cook the chicken for 6-7 minutes on each side or until fully cooked through. Once done, remove the chicken from the skillet and set it aside to rest.
While the chicken is cooking, steam the cauliflower florets until tender, about 10 minutes. Once the cauliflower is tender, transfer it to a blender or food processor and blend until smooth. Add almond milk as needed to achieve a creamy consistency.
Return the cauliflower mixture to the skillet, then stir in the Parmesan cheese, nutritional yeast (if using), onion powder, salt, and pepper. Heat the mixture over low heat until combined.
In a separate large skillet, sauté the zucchini noodles over medium heat for 2-3 minutes until just tender.
Slice the cooked chicken into thin strips.
Combine the zucchini noodles with the cauliflower Alfredo sauce in the skillet. Add the sliced chicken on top and stir everything together until well coated.
Serve hot, garnished with fresh parsley if desired.