Preheat oven to 425 °F
Cut off the end of each zucchini then, using a vegetable peeler, peel each zucchini into wide strips.
Transfer the zucchini strips to a plate then layer two strips vertically and two strips horizontally to make a cross. Repeat process with remaining strips.
Heat a pan over medium-high heat.
Add olive oil then garlic and sauté for 30-60 seconds.
Add spinach, salt and pepper. Sauté for 1-2 minutes, until wilted down.
Remove from heat and allow to cool for 10 minutes.
In a large bowl, add the spinach and garlic. Add the ricotta, basil, salt and pepper Mix until well combined.
Using a spoon or cook scoop, scoop approximately 1 Tbsp of the mixture and place in the middle of each zucchini noodle cross.
Fold each side to seal the ricotta mixture then flip over the ravioli so the seam side is on the bottom.
Pour the marinara sauce in a baking dish and spread over the bottom.
Evenly place the zucchini raviolis then top with mozzarella cheese.
Bake for 15-20 minutes.
Serve with fresh basil.