Begin by gathering all your ingredients. This will streamline the cooking process and make it feel less daunting.
In a large skillet, heat 1/2 cup extra virgin olive oil over medium heat. Add 6 cloves of minced garlic and sauté for about 1 minute until fragrant. Stir in 2 teaspoons dried oregano, 2 teaspoons dried basil, 1 teaspoon dried parsley, and 1 teaspoon crushed red pepper flakes. Season with kosher salt and pepper to taste. Sauté for another minute.
Add 1 pound of dry spaghetti to the skillet, along with 1 jar (24 ounces) of marinara sauce and enough water to cover the pasta (about 4 cups). Bring to a boil, then reduce to a simmer. Cook according to the package instructions until the spaghetti is al dente, stirring occasionally to prevent sticking.
In a mixing bowl, whisk together 4 eggs, 1 cup whole milk ricotta cheese, 1 1/2 cups shredded mozzarella cheese, and 1/2 cup grated parmesan cheese. Season with a pinch of salt and pepper.
Once the spaghetti is cooked, remove the skillet from heat. Gently fold in the egg and cheese mixture until well combined. Spread it evenly over the spaghetti. Preheat your oven to 375°F (190°C) and transfer the skillet to the oven. Bake for about 25-30 minutes until the top is golden and the cheese is bubbling.
Remove the skillet from the oven and let it cool for a few minutes. Top with fresh basil and/or oregano before slicing and serving. Enjoy your One-Pan Cheesy Spaghetti Pie with a side salad or some crusty bread for a complete meal!