Preheat the oven to 350 degrees F. Bring a large pot of water to a boil. Add the salt and cook the lasagna noodles to al dente, according to package directions. Drain and carefully lay the lasagna noodles out flat on a large piece of parchment paper. Let sit to cool.
In a medium bowl, combine the ricotta cheese, egg, garlic, spinach, artichoke hearts, parmesan cheese, basil, crushed red pepper, and nutmeg. Stir until well combined. Season with salt and pepper.
Spray a 9x13 baking dish with cooking spray. Line the bottom with marinara sauce, about 1/2 cup. Set aside.
Take about 1/4 cup of the ricotta spinach mixture and spread it evenly onto each lasagna noodle. Top each noodle with 2 tablespoons of mozzarella cheese and 2 tablespoons of marinara sauce. Carefully roll the noodles up and place them in the prepared pan. Top the lasagna rolls with the remaining marinara sauce and mozzarella cheese. Spray a large sheet of foil with cooking spray and cover the pan.
Place the pan in the oven and bake for 35 minutes. Remove the foil and bake for an additional 5 minutes, or until the cheese is melted on top. Remove from the oven and let sit for 5 minutes. Serve warm.
Note: To prepare the lasagna rolls in advance, roll them up, add the sauce and cheese and cover with foil and place in the fridge until ready to bake. I've made them a day before baking and they were still great. To freeze, bake and let cool to room temperature. Place in a freezer container and freeze. Reheat in the microwave. You can place a whole pan in the freezer and heat back up in the oven, but I like to freeze the rolls in individual servings for easy lunches and dinners.