Preheat the oven to 375°F (190°C).
Bring a large pot of salted water to a boil and cook the whole wheat penne until al dente; drain and set aside.
Heat the olive oil in a large skillet over medium-low heat. Add the chopped or torn spinach and cook until just wilted, about 3–4 minutes; remove from heat.
In a large mixing bowl, combine the cooked penne, marinara sauce, wilted spinach and drained artichoke hearts; toss to combine evenly.
In another bowl, mix the cottage cheese, shredded mozzarella, ricotta, egg white, dried oregano, black pepper, crushed red pepper flakes and salt until smooth.
Spread half of the penne mixture into a 9×13-inch casserole dish, top with half of the cheese mixture, then repeat with the remaining penne and cheese so the cheese mixture is on top.
Sprinkle the grated Parmesan over the top and add additional freshly ground black pepper if desired.
Bake in the preheated oven until hot and bubbly, about 30 minutes. Let rest a few minutes before serving.