Boil manicotti pasta for 5 minutes, then drain and set aside.
In a skillet over medium-high heat, warm oil for 30 seconds. Add garlic, cooking for another 30 seconds and stirring occasionally.
Add spinach and cook, stirring often, until wilted (2-3 minutes). Then, remove the skillet from heat.
In a medium bowl, combine ricotta, the spinach-garlic mix, salt, pepper, nutmeg, ½ cup mozzarella, and 2 tablespoons Parmesan.
Spread ¼ cup of Marinara sauce in the bottom of a small baking dish.
Stuff the manicotti tubes evenly with the ricotta mixture and place them in the dish.
Pour remaining ¼ cup of Marinara sauce over the stuffed manicotti and top with ½ cup of shredded mozzarella cheese and 1 tablespoon of grated Parmesan cheese.
Drizzle the remaining ¼ cup Marinara sauce over the manicotti and sprinkle with ½ cup mozzarella and 1 tablespoon Parmesan.
Cover the dish with foil and bake for 20 minutes.
Uncover and continue baking for another 10-15 minutes, until the cheese is melted.
Take the dish out of the oven and serve the manicotti hot.
Video
Notes
Don't overcook the pasta: Cook just until slightly firm, it will continue to soften in the oven.
Fill the pasta gently: Using a spoon or a small piping bag helps prevent tearing the manicotti tubes.
Cover with foil while baking: This helps the pasta cook evenly and prevents it from drying out.
Season to Taste: Adjust spices and seasonings to suit your palate.
Let it rest before serving: A short resting period allows the cheese to set.