Thinly slice the onions and heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the onions and sauté them slowly for 30–40 minutes, stirring occasionally, until they turn a rich, golden brown.

In the same skillet, reduce the heat slightly and add 4 tablespoons of butter. Once melted, whisk in ¼ cup of flour to form a roux, cooking for about 2 minutes. Gradually pour in 2 cups of heavy cream, stirring continuously until the mixture thickens.

Bring a large pot of salted water to a boil. Add 12 ounces of cavatappi macaroni and cook it according to package instructions until just under al dente, usually around 7-9 minutes.

Once the pasta is cooked and drained, return it to the pot and pour the béchamel sauce over the top. Gently toss everything together, ensuring the pasta is well-coated.

Preheat your oven to 350°F (175°C). Transfer the pasta mixture to a greased baking dish. Top with the remaining caramelized onions and sprinkle an even layer of breadcrumbs over the top.

Once baked, remove your French Onion Soup Pasta from the oven and let it cool for a few minutes before serving. Garnish with freshly chopped parsley.