Preheat your oven to 400°F and line a baking sheet with parchment paper for easy cleanup.
Place the chicken breast between two sheets of plastic wrap and pound to an even half-inch thickness.
In a shallow bowl, whisk the egg until smooth; in a second bowl, combine the almond flour, parmesan cheese, sea salt, black pepper, and garlic powder.
Dip the chicken breast into the egg wash, letting any excess drip off, then press firmly into the almond flour mixture until fully coated.
Place the breaded chicken on the prepared baking sheet and bake for 15 to 18 minutes, or until the internal temperature reaches 160°F.
Remove from the oven, spoon the marinara sauce over the center of the chicken, and top with the shredded mozzarella cheese.
Return to the oven for 3 to 5 minutes, or until the cheese is melted and bubbly.
Garnish with freshly chopped basil and serve immediately.