Roast the whole sweet potatoes at 400F (200C) for 45-60 minutes, until completely tender.
Split each one open along the top and fluff the flesh with a fork. Whip in the softened butter, maple syrup, white miso and cinnamon until smooth and creamy (the miso deepens the caramel flavour).
Sprinkle the demerara sugar evenly over the tops.
Brulee with a kitchen torch (or run under a hot broiler) until the sugar melts and caramelizes into a crackly top. Serve warm.
From @craveflash on Instagram. Ingredients are from the post's ingredient card; the method is reconstructed from the caption and video.