Start by cooking the zucchini and getting the sauce ready. In a large pot, heat the olive oil. Cook the zucchini coins until they are just tender, then remove them to a plate and set them aside. If needed, add a bit more oil to the pot, then add the onion with a pinch of salt and cook, stirring often, until they have softened up. Stir in the garlic and cook another minute or so, until fragrant. Then pour in the crushed tomatoes and stir in the sugar and seasonings.

Once the sauce begins to simmer, lower the heat and let it bubble gently. Heat a large pot of salted water over high heat. Once it boils, cook the penne pasta according to the package directions. Once the pasta is done, drain it, then return it to the pot and toss lightly with 1 tbsp of olive oil. Sprinkle the shaved parmesan over the pasta and set it aside.

While your waiting on the pasta water to come to a boil, start the chicken. In a large, deep skillet, heat the remaining 1 tbsp of olive oil over med-high heat. Once it's hot, add the chicken to the skillet and season it with salt and pepper. Cook until it's all browned and completely cooked through. Then place your chicken over top of the pasta.

Last, stir the spinach into the simmering sauce. Once it wilts down, stir the zucchini and mozzarella cheese cubes into it. Stir gently until the mozzarella begins to soften. Before it completely melts, remove the sauce from the heat and pour it over top of the chicken and pasta. Then serve.