Boil a large pot of salted water. Once boiling, add spaghetti and cook until al dente, about 8–10 minutes. Rinse briefly under cold water.

In a large mixing bowl, combine drained spaghetti, marinara sauce, and ground beef or sausage if using. Stir until well coated.

Transfer the mixture into a greased bundt pan or shape on a baking sheet, creating folds to mimic a brain's appearance.

Sprinkle cheese generously over the spaghetti mixture, ensuring it covers the surface completely.

Preheat oven to 375°F. Bake the dish for about 20-25 minutes until cheese is bubbly and lightly golden.

Let it cool slightly before inverting onto a platter. Drizzle extra marinara on top for added effect.