Preheat your oven to 375°F (190°C).
In a large mixing bowl, combine the shredded chicken, marinara sauce, ricotta cheese, garlic powder, Italian seasoning, salt, and black pepper. Mix until well combined.
Spread the chicken mixture evenly in a greased 9x13-inch baking dish.
Sprinkle the mozzarella cheese and Parmesan cheese evenly over the top of the chicken mixture.
If using, mix the almond flour with olive oil in a small bowl and sprinkle it over the cheese layer for added crunch.
Bake in the preheated oven for 25-30 minutes, or until the cheese is bubbly and golden brown.
Remove from the oven and let it cool for about 5 minutes before serving. Garnish with fresh basil if desired.