Preheat your oven to 400°F. While it heats, bring a large pot of generously salted water to a boil—this seasons the pasta as it cooks. Add the penne and cook for 1 minute less than the package directions indicate. This slight undercooking is crucial because the pasta will continue cooking in the oven and absorb liquid from the sauce, preventing it from becoming mushy. Drain the pasta well, but don't rinse it; the starch on the surface helps bind everything together.

While the pasta cooks, thaw the spinach by placing it in a colander and running warm water over it, then squeeze out as much moisture as possible—excess liquid will make your bake watery. Finely mince the fresh garlic cloves; I like to do this by hand to ensure the pieces are small and evenly distributed throughout the dish for consistent garlic flavor in every bite.

In a large bowl, combine the drained pasta from Step 1 with the marinara sauce, cottage cheese, thawed spinach from Step 2, minced garlic, dried oregano, and torn basil leaves. Season generously with salt and pepper, then stir everything together until evenly combined. The cottage cheese will seem chunky at first, but it will meld into a creamy sauce as it bakes. Transfer this mixture to a 9x13 inch baking dish, spreading it in an even layer.

Sprinkle the shredded mozzarella evenly over the top of the pasta mixture. Bake in the preheated 400°F oven for 20 minutes, until the pasta is heated through and the cheese is melted and beginning to bubble around the edges.

Turn on the broiler and broil the pasta bake for 2 minutes until the cheese develops light golden-brown spots on top. Watch carefully to avoid burning. Remove from the oven and let rest for 5-10 minutes before serving—this allows the filling to set slightly and makes serving much cleaner.