Each noodle of penne pasta is coated in a luscious, homemade cheese sauce made with a combination of aged sharp Cheddar cheese and Monterey Jack, then topped with buttery crushed Ritz cracker crumbs for an irresistible golden crust.
Bring a large pot of heavily salted water to a boil. Add the penne pasta and cook until just al dente, 6 minutes. Drain the pasta and set the cooked noodles aside.
Heat a large saucepan over medium heat. Add 3 tablespoons (43g) of the butter and allow to melt, then whisk in the flour, continuing to stir until pale brown, about 1 minute.
Whisk in the milk and bring to a simmer. Continue to simmer over medium-low heat until the mixture thickens, about 10 minutes.
Whisk in the Cheddar cheese and the Monterey Jack cheese until the mixture becomes smooth.
Add the cooked pasta to the cheese mixture and stir until the mixture is thoroughly combined. Add to a baking dish or large cast iron pan.
Melt the remaining butter. In a small bowl stir together the Ritz cracker breadcrumbs and butter until combined.
Sprinkle the top of the macaroni and cheese mixture with remaining cheese and crumbled cracker topping and bake until the top is golden brown, about 20 minutes. Serve immediately.
Notes
To make ahead: Assemble your mac and cheese ahead of time and store it covered in the fridge up to 2 days before baking.