Preheat your oven to 375°F and bring a large pot of salted water to a rolling boil. Cook the manicotti pasta according to package directions until just al dente—approximately 8-10 minutes. Drain gently and lay flat on parchment paper to prevent sticking together.

While pasta cooks, heat olive oil in a large skillet over medium-high heat and add diced onion. Sauté for 3-4 minutes until softened, then add minced garlic and cook for another minute until fragrant. The aromatics create the flavor foundation for your meat sauce.

Add ground beef to the skillet and cook, breaking it apart with a spoon, for 5-7 minutes until completely browned. Drain excess fat if necessary, then stir in marinara sauce, Italian seasoning, salt, and black pepper. Simmer this sauce for 5 minutes to allow flavors to meld together beautifully.

Combine ricotta cheese, mozzarella, parmesan, egg, and fresh basil in a large mixing bowl until the mixture is smooth and creamy. Taste and adjust seasonings as needed—this is your cheese filling heart.

Using a small spoon or piping bag, carefully fill each manicotti tube with the golden tender manicotti cheese mixture, reserving a little sauce for the top layer. Spread a thin layer of meat sauce on the bottom of a 9x13 baking dish.

Arrange filled manicotti tubes seam-side down in a single layer, then cover with remaining meat sauce and cheese mixture on top. Bake uncovered for 40 minutes until the top is golden and bubbly around the edges.

Remove from oven and let rest for 5 minutes before serving—this allows the sauce to set slightly so portions hold together beautifully on the plate.