Step 1

Preheat oven to 350 degrees F.

Step 2

Lightly grease a 9x13 baking dish with butter or with non-stick cooking spray. Set aside.

Step 3

Cook pasta per box directions, aim for al dente. Drain, mix with olive oil, and set aside.

Step 4

Place a large saucepan over medium heat and once it's hot add the butter. Stir and melt the butter, carefully not to burn it.

Step 5

Add the flour and whisk until fully combined with the melted butter.

Step 6

While still whisking, little by little add the milk, stirring to combine. Take your time and don't rush through this step.

Step 7

In a small bowl, whisk cream and cornstarch until fully combined and cornstarch is fully dissolved. Add the mixture to the pan. Stir to combine.

Step 8

Add the evaporated milk and stir to combine. Add onion powder, garlic powder, ground thyme, paprika, mustard, red pepper flakes and salt.

Step 9

Stir over medium heat, bring the mixture to a boil, and let it simmer for about 2 minutes.

Step 10

Stir in sour cream and cream cheese until fully combined. If the sauce is too thick you can add more milk or some chicken broth. Taste and adjust for salt and pepper.

Step 11

Reduce heat to low and add 3 cups of cheddar cheese and 1 cup of mozzarella cheese, freshly grated or pre-shredded. Stir to combine, until the cheese is fully melted.

Step 12

Remove the pan from heat and add the cooked elbows macaroni. Stir to combine.

Step 13

Transfer the mixture to the prepared casserole dish.

Step 14

In a medium bowl combine cracker crumbs with melted butter and stir using a fork until fully combined.

Step 15

Level the top with a spatula and sprinkle 1 cup of mozzarella cheese and 1 cup of cheddar cheese evenly over the surface of the casserole.

Step 16

Sprinkle the Buttery Cracker Topping evenly over the surface and top with chopped cooked bacon if using.

Step 17

Bake the casserole uncovered in the preheated oven for 25-30 minutes. Until the top is golden brown and bubbly.

Step 18

Remove from oven and let it rest for 15 minutes before serving.

Step 19

Serve topped with extra bacon and if desired chopped parsley.