Preheat oven to 425°F and line a baking sheet with parchment paper.
Butterfly the chicken breast or pound it to an even 1/2-inch thickness for uniform cooking.
In a shallow bowl, whisk the egg. In another bowl, combine almond flour, parmesan, garlic powder, oregano, salt, and pepper.
Dip the chicken into the egg wash, then dredge in the almond flour mixture, pressing firmly to create a thick, crispy coating.
Place chicken on the baking sheet, drizzle with olive oil, and bake for 15 minutes until the crust is golden.
Remove from oven, spoon marinara sauce over the chicken, and top with mozzarella cheese.
Return to the oven for 5 minutes or until the cheese is bubbly and melted.
While chicken finishes, lightly steam or sauté the zucchini noodles for 2 minutes until tender, then serve the chicken on top.