Preheat the oven to 350°F (175°C). Spread about 1 cup of marinara sauce over the bottom of a 9 x 13 inch baking dish.
Cook the lasagna noodles in a large pot of boiling salted water according to package directions until pliable but not overcooked, then drain and lay flat on a work surface.
In a medium bowl, combine the squeezed spinach, chopped artichoke hearts, ricotta, grated Parmesan, minced garlic, the large egg, 1/2 teaspoon kosher salt, and a few grinds of black pepper; stir until evenly mixed.
Spoon about 1/3 cup of the spinach-artichoke filling onto one end of each lasagna noodle and spread into an even layer, leaving a small border at the edges.
Carefully roll each noodle up from the filled end and place seam-side down in the prepared baking dish; repeat with all noodles to make 8 rolls.
Pour the remaining marinara sauce evenly over the rolls and sprinkle about 1 tablespoon of shredded mozzarella on top of each roll.
Cover the dish with foil and bake for 40 minutes, until the rolls are heated through and the cheese is melted.
Remove from the oven and let rest briefly. To serve, spoon additional marinara on plates if desired and garnish with chopped parsley.
