Prepare the Mac & Cheese:
Cook macaroni in salted water until al dente; drain.
Melt butter in a saucepan, whisk in flour, and cook 1 minute.
Gradually add milk, stirring until slightly thickened.
Mix in cheese until melted, season, then fold in pasta. Set aside.
Make the Meatloaf Base:
In a large bowl, combine all meatloaf ingredients. Mix gently—avoid overworking.
Assemble:
Preheat oven to 375°F (190°C). Line a baking sheet.
Flatten ⅔ of the meat mixture into a rectangle (~1" thick).
Spoon mac & cheese into the center, leaving edges bare.
Top with remaining meat, sealing completely. Shape into a loaf.
Glaze & Bake:
Mix ketchup, brown sugar, and mustard; spread over the loaf.
Bake 50–60 minutes (internal temp: 160°F/71°C).
Rest 10–15 minutes before slicing.
Pro Tip: Customize with jalapeños or bacon for extra flair! This dish delivers gooey, cheesy goodness inside a perfectly seasoned meatloaf—comfort food at its finest