Add 1 tablespoon of butter to a large skillet. Heat over medium-high heat.
Add the prosciutto to the heated pan, and cook until crispy, but not burned.
Remove the prosciutto from the skillet, and set it aside.
Add the other tablespoon of butter to the skillet. Add diced onion to the skillet and cook for approximately 5 minutes, or until the onion is translucent and slightly caramelized.
Add avocados to a large glass bowl, and using a fork, mash well.
Add the garlic powder, salt, and pepper to the bowl. Add the chicken bone broth and mix well. (The avocado sauce should be thick like a batter.)
Drain the zucchini noodles well and add to the skillet with the onions.
Cook for 1-2 minutes, or until zucchini is warmed through.
Add the avocado sauce to the skillet. Add the shredded parmesan cheese. Mix well, and cook for 2-3 minutes, or until the cheese is melted and the mixture is warm.