Prepare the ingredients: Rinse the butternut with water. Cut out the top and bottom ends of the butternut. Remove the seeds and horizontally cut the butternut in half.
Flavour the butternut: Place the halved butternuts in a casserole. Add one tablespoon of butter inside the hollow part of each butternut. Sprinkle brown sugar on all the inside surfaces of the butternut.
Bake the butternut: Place the casserole of butternut in a preheated oven at 145ºC or 295ºF. Bake the butternut for fifty minutes with the fan on, or sixty minutes without the fan. Poke the butternut with a fork to see if it is done. If the fork does not go through with ease, bake for another five to ten minutes. Add toppings such as whipping cream, extra sugar, or honey, and serve the baked butternut while it is hot.