Now for the fun part! Let’s get cooking!

Start by preheating your oven to 375°F (190°C). This will ensure that it’s hot and ready for those bubbling stuffed shells.

In a saucepan, warm the marinara sauce over low heat. If you're feeling adventurous, now’s the time to throw in a pinch of red pepper flakes or some chopped fresh basil. Let it simmer gently while you move on to the next steps.

In a skillet over medium heat, cook the ground beef until browned. I like to use a wooden spoon to break it apart while it cooks. Once it’s browned, drain any excess fat, and add in the garlic powder and oregano, blending everything together for a couple of minutes. It’s all about those flavors mingling!

In a large bowl, combine the ground meat mixture, ricotta cheese, spinach, beaten egg, and half of the mozzarella cheese. Mix it all together until you get a beautiful, cohesive filling. I usually do this by hand, which feels closer and more personal, you know?

Grab those jumbo pasta shells! Using a spoon, fill each shell with a generous amount of the meat and cheese mixture. Don’t be shy! Place the filled shells with the open side facing up into a baking dish.

Spread half of the warm marinara sauce on the bottom of your baking dish. It helps prevent the shells from sticking and adds flavor. Then, carefully arrange the stuffed shells in the dish. Once all the shells are snugly in place, pour the remaining marinara sauce on top.

Sprinkle the remaining mozzarella cheese over the stuffed shells and top it all with some grated Parmesan for good measure. Cover the dish with aluminum foil and bake for 25 minutes. After that, remove the foil and bake for another 15-20 minutes until the cheese is golden and bubbly.

Take a moment to admire your handiwork. It’s a feast for the eyes! Let it cool for a few minutes before serving, then garnish with some fresh basil or extra grated Parmesan if you’re feeling fancy.