Baked Southern macaroni and cheese casserole with a creamy, custard-like filling and golden top is a vegetarian family comfort classic. This rich, cheesy dish is a holiday table essential that both kids and adults devour.
Preheat oven to 350°F. Generously butter a 2-quart baking dish for a nonstick finish.
Boil elbow macaroni in a large pot of salted water until just al dente, about 1 minute less than package instructions. Drain thoroughly so no excess water dilutes the custard.
While pasta cooks, whisk together eggs, whole milk, salt, pepper, mustard powder, and paprika in a bowl until smooth.
Fold drained macaroni, melted butter, and half the shredded cheddar cheese into the egg-milk mixture. Stir well to ensure cheese is evenly distributed.
Pour the mixture into the prepared baking dish, top evenly with the remaining cheese, and bake uncovered for 35-40 minutes until set and the surface is golden and bubbling. Let rest 5 minutes before serving for best slicing.