Steam the sweet potato with the skin on, then mash it.
Mix the cream cheese and sugar until smooth.
Add eggs one at a time, mixing after each addition.
Add the mashed sweet potato and heavy cream, and mix well.
Sift cake flour into the mixture and stir until combined.
Pour the batter into a pan lined with baking paper.
Bake in a preheated oven at 180°C for 35–40 minutes.
Cool completely, then refrigerate until chilled.