Grate the zucchinis using a grater and place them in a large bowl. Squeeze out excess moisture with a clean kitchen towel or paper towels.
To the grated zucchini, add the cooked quinoa, breadcrumbs, Parmesan cheese, eggs, parsley, garlic powder, onion powder, salt, and pepper. Mix well until all ingredients are combined.
Heat a non-stick pan over medium heat and lightly grease it with non-stick cooking spray or oil.
Use a spoon or your hands to form small cakes (about 3 inches in diameter) from the mixture and place them in the heated pan.
Cook the cakes for about 5 minutes per side, or until golden brown and cooked through. You may need to cook in batches.
While the cakes are cooking, mash the avocado in a small bowl and mix in lime juice, salt, and pepper to taste.
Once the cakes are done, serve them hot, topped with the avocado mixture.