Spinach and Ricotta Zucchini Cannelloni



2 large and wide Zucchini, washed and unpeeled
1x 400g | 14oz can crushed tomatoes (or pasta sauce of choice/or Passata)
500g | 18oz frozen spinach, thawed
500g | 18oz Ricotta
2 eggs
3 garlic cloves, crushed (or 2 teaspoons garlic powder)
¾ cup mozzarella cheese, divided
Salt to taste