Chop the zucchini in thin slices. You can either use a mandoline or vegetable peeler. You should get around 20 strips from each zucchini. The strips should be thin enough to fold up without breaking.
Place five minced garlic cloves in a skillet over medium heat with two tablespoons of olive oil. Cook until fragrant.
Add spinach to the skillet and stir for 2 minutes.
Remove the skillet from the stove and add ricotta cheese, salt and ground pepper. Stir to combine.
Place spinach with ricotta in a medium bowl and process it with a hand blender. You can also use a food processor too.
Preheat oven to 400 degrees F.
To make the sauce, place the tomato sauce, one garlic clove and dried oregano in a blender and pulse until smooth.
Place the sauce in the bottom of an 8’’ x 8" baking dish.
To shape the ravioli, place three slices of zucchini, one over the other, making a cross. If one strip is too thin, simply put one extra over it.
Add the cheese mixture in the middle of the cross; one full spoon will be enough. Then fold up the strips, one at a time, until the ravioli is closed.
Lay the raviolis over the tomato sauce and top them with remaining 1 cup shredded mozzarella cheese.
Bake them for 15-20 minutes or until mozzarella is melted and the zucchinis are soft.