Combine the almond flour, parmesan cheeses, onion powder and garlic powder. Mix until well incorporated. Spread the mixture in a thin layer on a plate. Add the heavy cream, and egg to a small bowl, and fork whisk to combine. Heat about an inch of oil in a high-sided skillet or dutch oven over medium-high heat. Coat the zucchini slices in the breading, dredge in the egg wash, and then coat in the breading again. Gently place the breaded zucchini into the hot oil and fry until the breading is crispy on both sides, about 2 to 3 minutes each side. Try not to flip the zucchini too many times or you will lose your breading. Line a plate with paper towels and as you remove the zucchini from the pan, place them on the paper towels to absorb any excess grease.