Ingredients:

  • 1 lb (450 g) elbow macaroni
  • 1 tbsp (15 g) kosher salt, for the cooking water
  • Nonstick cooking spray, for the baking dish
  • 4 tbsp (57 g) unsalted butter
  • ⅓ cup (42 g) all-purpose flour
  • 2 cups (480 ml) whole milk, warmed
  • 1 cup (240 ml) heavy cream
  • 12 oz (340 g) sharp cheddar, freshly shredded from a block (about 3 cups)
  • ½ cup (50 g) finely grated Parmesan
  • 1 tsp (3 g) dry mustard powder
  • ½ tsp (1.5 g) garlic powder
  • ¾ tsp (4.5 g) fine sea salt, adjusted to taste
  • ¼ tsp (0.5 g) black pepper
  • ½ cup (30 g) panko breadcrumbs
  • 2 tbsp (28 g) unsalted butter, melted

Instructions:

  1. Heat the oven to 375°F (190°C). Lightly coat a 9×13-inch baking dish with nonstick cooking spray.
  2. Shred the cheddar and grate the Parmesan. Set both aside in separate bowls.
  3. Warm the milk in a microwave-safe measuring cup for about 1 minute, until warm to the touch but not hot.
  4. Bring a large pot of water to a boil and add the kosher salt. Cook the macaroni for 1 minute less than the package directions, so it is firm when drained. It will finish in the oven.
  5. While the pasta cooks, melt 4 tbsp butter in a medium saucepan over medium heat. Whisk in the flour and cook for about 1 minute, stirring constantly, until nutty-smelling and resembling wet sand. Do not let it brown.
  6. Slowly pour in the warm milk and heavy cream, about ½ cup at a time, whisking until smooth after each addition.
  7. Continue cooking over medium heat, stirring often, for 5 to 7 minutes, until the sauce bubbles gently and thickens enough to coat the back of a spoon.
  8. Remove the saucepan from the heat. Whisk in the mustard powder, garlic powder, fine sea salt, and black pepper.
  9. Add the cheddar a handful at a time, stirring until each addition melts before adding the next. Stir in the Parmesan last. The sauce should look glossy and smooth.
  10. Drain the pasta and return it to the pot. Pour in the cheese sauce and stir until every noodle is coated.
  11. Spread the mixture evenly in the prepared baking dish.
  12. Stir the 2 tbsp melted butter into the panko and sprinkle the mixture evenly over the top.
  13. Bake uncovered for 20 to 25 minutes, until the edges bubble vigorously and the topping is golden brown.
  14. Rest for 10 minutes before scooping. The sauce thickens as it sits.