Preheat oven to 375 degrees.
Grate all of the cheese. This is actually my favorite step! Cut the muenster into small chunks. I do this because it does not grate as easy. Cook the pasta in accordance with the instructions on the package.
Drain the macaroni and rinse with cold water. This is important. You want the pasta to cool so that it does not continue to cook. The pasta will cook again while baking in the oven. Over-cooked pasta results in a terrible texture.
Heat a sauce pan on medium heat. Add the butter and allow it to melt.
Once melted, add the flour and whisk.
This will create a roux. Continue to whisk until the four is fully combined.
Add the milk and heavy whipping cream and stir.
Add half of the shredded cheese and stir until the cheese is melted.
Add the seasonings and taste repeatedly. This step is important because you don’t want bland mac and cheese
Return the pasta to the large pot. Drizzle the liquid mixture over the pasta and stir until fully combined.
Spray a 9 x 13 inch baking pan with cooking spray.
Begin to layer in the pasta. Start with the pasta, then add a layer of all of the shredded cheese and muenster chunks.
Add another layer of pasta, and then another layer of cheese.
Ensure there is adequate liquid throughout these steps (additional milk works well). This can be tricky. You do not want the dish to appear like soup, but you do not want it to be dry.
This step is important because without adequate liquid the dish will dry out while baking.
Bake for 25-45 minutes until the cheese has melted and is bubbly. I like for the crust on top to turn a deep golden brown, which takes more time. Use your judgment based on what works for you.
Cool before serving.