Preheat your oven to 375°F.
Slice the zucchini lengthwise into thin strips to serve as the lasagna layers. Set aside a few slices for topping.
In a skillet, warm the olive oil over medium heat. Add the lean ground turkey and cook, breaking it up with a spatula, until browned and fully cooked. Season with Italian seasoning, garlic powder, salt, and pepper.
Once the turkey is cooked, mix it with tomato sauce in the skillet. Stir in the fresh spinach until wilted.
In a small bowl, combine the low-fat ricotta cheese with a pinch of salt and pepper.
In an oven-safe baking dish, layer some zucchini slices on the bottom. Spread a layer of the turkey-tomato mixture over the zucchini, then dollop and gently spread half of the ricotta mixture over the meat. Repeat with another layer of zucchini, turkey mixture, and the remaining ricotta.
Top with the remaining zucchini slices.
Cover with foil and bake for 20 minutes. Remove the foil and bake for another 10 minutes to allow the top to lightly brown.
Let the lasagna rest for a few minutes before serving.