Steam the tempeh block for 10 minutes to soften the texture and remove any natural bitterness.
Crumble the steamed tempeh into a large mixing bowl and allow it to cool slightly before adding other ingredients.
Add the egg, nutritional yeast, garlic powder, onion powder, oregano, sea salt, and black pepper to the crumbled tempeh.
Mash the mixture together thoroughly with a fork or clean hands until it is uniform and holds together when pressed.
Form the seasoned tempeh mixture into 12 small, uniform meatballs, pressing firmly to ensure they stay intact.
Heat a large non-stick skillet over medium heat and lightly coat the surface with half of the olive oil.
Sear the meatballs for 2-3 minutes per side, turning carefully, until a golden-brown crust forms on all sides.
Pour the tomato puree over the meatballs in the skillet, reduce the heat to low, and simmer for 5 minutes.
In a separate small pan, sauté the zucchini noodles with the remaining olive oil for 2 minutes until just tender.
Divide the zucchini noodles between plates and top with the meatballs and the warm marinara sauce from the pan.