1. PREHEAT the oven to 375ºF.
2. PLACE the pumpkin flat-side-down or remove thin slice from one side so the pumpkin will be stable. With a sharp knife, cut the pumpkin in half horizontally, slightly above stem, to form a bowl. Remove the fiber and seeds. With a spoon or an ice cream scoop, scrape out some of the flesh so shell has a thickness of 3/4 to 1 inch.
3. SPRAY the top edge of the pumpkin with cooking spray or brush lightly with oil; then place it cut-side down on a pizza pan or baking sheet. Bake for 45 to 60 minutes or until the pumpkin still holds it shape but the flesh is cooked and can be pierced easily with a toothpick. While pumpkin bakes…
4. COOK the macaroni according to package instructions. Drain and set aside.
5. MAKE the cheese sauce: Melt the butter over medium heat in a large saucepan. Sprinkle the flour into the butter and whisk constantly until there is a thick, smooth paste with nutty aroma (about 5 minutes).
6. ADD the mustard, red pepper and Worcestershire. Gradually whisk in the milk and continue stirring until the sauce thickens and returns to a simmer.
7. REDUCE the heat to low. Add 7 cups of the cheese and stir until melted. Add the macaroni, stirring until well coated; remove from the heat.
8. TURN the baked pumpkin over with oven mitts. Place it in a large shallow baking dish (from which you’ll serve it), or leave it on the baking sheet. Fill the pumpkin with the macaroni mixture and top with the remaining cheese and breadcrumbs. (Put any mac and cheese that won’t fit into another small baking dish).
9. BAKE until the filling is puffed and golden, about 40 to 50 minutes longer (a smaller baking dish will be done sooner). Let stand for about 10 minutes to settle before serving. Garnish and serve.