Step 1: Prepare the Noodles : Bring a large pot of salted water to a boil. Add lasagna noodles and cook until al dente (about 8–10 minutes). Drain and lay noodles flat on parchment paper or lightly oiled foil to prevent sticking.
Step 2: Make the Spinach and Cheese Filling : In a mixing bowl, combine ricotta, 1 cup mozzarella, Parmesan, egg, garlic, Italian seasoning, salt, and pepper. Stir in chopped spinach until evenly mixed. Taste and adjust seasoning if needed.
Step 3: Assemble the Roll-Ups : Spread 1–2 tablespoons of the spinach-ricotta filling evenly along each noodle. Gently roll each noodle from one end to the other. Place the roll-ups seam-side down on a baking tray.
Step 4: Prepare the Baking Dish : Preheat the oven to 375°F (190°C). Spread 1 cup of marinara sauce on the bottom of a 9x13-inch baking dish. Arrange the lasagna roll-ups on top in a single layer. Pour the remaining sauce evenly over the roll-ups. Sprinkle the remaining ½ cup mozzarella on top.
Step 5: Bake : Cover with aluminum foil and bake for 20 minutes. Remove the foil and bake an additional 10–15 minutes, until bubbly and golden. Let it rest for 5 minutes before serving.