Cook the pasta according to the package directions, until al dente. Drain the pasta and reserve ½ cup of the pasta water. Set aside.
In a large skillet or saucepan, melt the butter over medium heat. Whisk in the flour, onion powder, garlic powder and Dijon mustard. Cook for 1 to 2 minutes, stirring constantly.
Gradually whisk in the pickle juice, whole milk and heavy cream. Cook, stirring constantly until the mixture begins to thicken, about 3 to 4 minutes.
Reduce the heat to low. Stir in the Dijon mustard, cheddar cheese, and Havarti cheese. Continue stirring until the cheese is fully melted and the sauce is smooth. Season with salt and pepper to taste.
Add the cooked pasta to the cheese sauce and toss to coat. If the sauce is too thick, stir in some of the reserved pasta water to reach your desired consistency.
Stir in the chopped dill pickles and dill.
Preheat the oven to 400℉. Transfer the mac and cheese to a greased 9x13 inch baking dish. Sprinkle the crushed potato chips on top.
Bake for 10 to 15 minutes or until the topping is crispy and golden. Garnish with more fresh dill if you like.