Caramelize the Onions: Thinly slice two large onions and heat 2 tablespoons of olive oil in a large skillet over medium heat. Add the onions and a pinch of salt, stirring occasionally for 30-40 minutes until deep golden brown and fragrant.

Prepare the Béchamel Sauce: Push onions to one side of the skillet and melt 2-3 tablespoons of butter. Whisk in 2 tablespoons of flour, then gradually pour in 1 cup of heavy cream while whisking continuously until the sauce thickens.

Combine Ingredients: Stir two-thirds of the caramelized onions into the béchamel sauce, followed by 1 cup of grated Parmesan cheese, 1 teaspoon of oregano, and salt and pepper to taste.

Cook the Pasta: In a large pot, bring salted water to a boil, then add 8 ounces of cavatappi macaroni. Cook according to package instructions until al dente, typically 8-10 minutes. Drain and reserve about 1/2 cup of pasta cooking water.

Mix and Bake: Combine the cooked pasta with the béchamel sauce in the skillet, adding a splash of reserved pasta water if needed. Transfer to a greased baking dish, top with remaining caramelized onions and breadcrumbs. Bake at 350°F (175°C) for 10-15 minutes until golden.