Begin by bringing a large pot of salted water to a rolling boil. Add spaghetti and cook according to package instructions until al dente, usually around 8-10 minutes. When done, drain the pasta and set it aside, letting the steam dissipate while you prepare the rest of the ingredients.

In a large skillet over medium heat, add ground beef or sausage, breaking it up with a spatula. Cook until browned and fully cooked, about 5-7 minutes, then drain the excess fat.

In a mixing bowl, combine the cooked spaghetti, marinara sauce, browned meat, and half of the cheese. Stir well until all ingredients are evenly coated.

Grease a bundt pan or line a baking sheet with parchment paper. Transfer the spaghetti mixture into the mold, using a spoon to shape and press it down to create the brain-like appearance.

Preheat your oven to 375°F (190°C). Once heated, sprinkle the remaining cheese over the top of the pasta mold, adding a drizzle of extra marinara for a 'blood' effect. Bake for about 25-30 minutes.

After baking, carefully remove the dish from the oven and let it cool for about 5-10 minutes before serving.