3 cups whole milk, divided
2 cups uncooked elbow macaroni
1/2 Tbsp. salt
1/2 Tbsp. pepper
3/4 cup shredded cheddar cheese
3/4 cup shredded mozzarella cheese
1 cup seasoned panko bread crumbs
Combine 2 cups of milk, macaroni, salt, and pepper in a large skillet over medium-high heat. Bring to a boil, stirring constantly to prevent sticking, then turn the heat down to medium-low heat and cook, stirring, until milk has reduced to a thick sauce. Add the remaining 1 cup of milk and cook until pasta is al dente and milk has reduced by about half. Add the cheddar and mozzarella, stirring until cheese is melted and pasta is evenly coated.
Sprinkle the bread crumbs evenly across the top of the mac ‘n’ cheese, using your hand to press them down into the crevices. Spray the bread crumbs with cooking spray in a circular motion for about 4 seconds to coat them evenly.
Broil on high until bread crumbs are golden brown and toasty, about 5 minutes, watching carefully to make sure the bread crumbs don’t burn. Serve!