Step 1: Cook the Pasta

1. Bring a large pot of salted water to a boil.
2. Cook the jumbo pasta shells until al dente, following the package instructions (usually 10–12 minutes). Avoid overcooking, as the shells will bake later.
3. Drain the shells and rinse them with cold water to prevent sticking. Set aside.

Step 2: Prepare the Beef Filling

1. In a large skillet, heat the olive oil over medium heat.
2. Add the ground beef and cook until browned, breaking it up into small pieces with a wooden spoon. Season with salt, pepper, and Italian seasoning.
3. Remove the skillet from heat and let the beef cool slightly.
4. In a mixing bowl, combine the ricotta cheese, mozzarella cheese, Parmesan cheese, egg, garlic powder, and onion powder. Mix until well combined.
5. Fold the cooked ground beef into the cheese mixture, stirring gently until evenly incorporated.

Step 3: Prepare the Sauce

1. In the same skillet used for the beef, heat 1 tbsp olive oil over medium heat.
2. Add the minced garlic and sauté until fragrant, about 1 minute.
3. Stir in the marinara sauce and red pepper flakes (if using). Simmer for 5 minutes.

Step 4: Stuff the Shells

1. Preheat your oven to 375°F (190°C).
2. Spread 1 cup of marinara sauce on the bottom of a 9×13-inch baking dish.
3. Using a spoon or piping bag, fill each cooked pasta shell with the ricotta beef mixture. Arrange the stuffed shells in the baking dish, open side up.
4. Pour the remaining marinara sauce evenly over the stuffed shells.

Step 5: Bake the Dish

1. Cover the baking dish with aluminum foil and bake in the preheated oven for 25 minutes.
2. Remove the foil, sprinkle additional mozzarella and Parmesan cheese on top, and bake uncovered for another 10 minutes, or until the cheese is melted and bubbly.

Step 6: Garnish and Serve

1. Remove the dish from the oven and let it cool for 5 minutes.
2. Garnish with fresh basil leaves and additional Parmesan cheese before serving.