Butterfly the chicken breast by slicing it horizontally to ensure a thin, even thickness for uniform cooking.
Whisk the egg in a shallow bowl until well combined.
In a separate shallow dish, mix together the almond flour, parmesan cheese, garlic powder, oregano, sea salt, and black pepper.
Dip the chicken breast into the whisked egg, allowing any excess to drip off, then press it firmly into the almond-parmesan mixture until fully coated.
Heat the olive oil in a large skillet over medium heat.
Place the chicken in the skillet and cook for 5 to 7 minutes per side until the crust is golden brown and the internal temperature reaches 165 degrees Fahrenheit.
While the chicken cooks, warm the marinara sauce in a small saucepan over low heat.
Remove the chicken from the skillet and let it rest; in the same skillet, sauté the zucchini noodles for 2 minutes until just tender.
Serve the crispy chicken over the zucchini noodles and top with the warm marinara sauce.