Preheat your oven to 425 degrees F. Line a rimmed baking sheet with foil and fit it with a wire rack. Spray the rack with olive oil.
Pat the chicken breasts dry. Season them on both sides with kosher salt, black pepper, and garlic powder.
In a shallow bowl or a Pyrex baking dish, whisk the egg with a tablespoon of water.
In another shallow bowl, mix together the almond meal and Parmesan.
Dip each chicken breast in the egg, then dredge it in the almond meal mixture. Use one hand for the egg mixture and one hand for the almond meal mixture.
Transfer the coated chicken breasts to the prepared wire rack. Spray their tops with olive oil. Bake them for 15 minutes.
Remove the pan from the oven but keep the oven on. Top each chicken breast with about 2 tablespoons of marinara sauce and 1 slice of provolone.
Return the chicken breasts to the oven for 5 more minutes, until they are cooked through, their internal temperature reaches 165 degrees F, and the cheese is melted.
Transfer the chicken to plates, top with chopped basil, and serve.
Video
Notes
*Bigger ones will need more time in the oven, and then you run the risk of burning the coating. If you do use bigger ones, you'll probably need to bake them for 20-25 minutes. If that's the case, loosely cover them with foil after the first 15 minutes to protect them from burning.