Boil the macaroni in salted water for about 4–5 minutes, just until slightly undercooked. This ensures the pasta doesn’t become mushy as it cooks in the Crockpot.
In a medium-sized bowl, whisk together the evaporated milk, whole milk, eggs, Dijon mustard, garlic powder, salt, and pepper. This mixture will form the creamy base for your mac and cheese.
Place the par-cooked macaroni in the Crockpot. Add the cubed butter, 2 cups of shredded cheddar cheese, mozzarella cheese, and Parmesan cheese. Pour the liquid mixture over the pasta, ensuring everything is well-coated. Stir gently to combine.
Cover the Crockpot with the lid and cook on low heat for 2–3 hours, stirring every 30 minutes to distribute the cheese and ensure even cooking.
While the mac and cheese is cooking, heat 1 tablespoon of olive oil in a skillet over medium heat. Add the panko breadcrumbs and toast them, stirring frequently, until golden brown.
Once the pasta is tender and the sauce is creamy, stir in the remaining ½ cup of cheddar cheese. Turn off the Crockpot, cover it again, and let the cheese melt for 5 minutes.
