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 using a meat mallet or heavy pan.
In a shallow bowl, whisk the egg until smooth. In a second shallow bowl, combine the almond flour, parmesan, garlic powder, oregano, salt, and pepper.
Dip the chicken breast into the egg wash, letting any excess drip off, then press firmly into the almond flour mixture until evenly coated on both sides.
Place the coated chicken on the prepared baking sheet and bake for 12 to 15 minutes until the crust is golden and firm.
Remove the tray from the oven and spoon the marinara sauce over the center of the chicken, then sprinkle with the shredded mozzarella.
Return to the oven for an additional 5 minutes, or until the cheese is melted and bubbly and the internal temperature reaches 165°F.
Let the chicken rest for 2 minutes, then garnish with freshly chopped basil and serve.