Preheat the oven to 170°C (338°F).
Steam the persimmon with the skin on, then mash it.
Add cream cheese, mashed persimmon, Greek yogurt, and erythritol, and mix well.
Beat the eggs and add them to the mixture, stirring with a whisk.
Sift in almond flour, protein powder, and baking powder, then mix.
Pour the batter into a pound cake pan lined with parchment paper.
Bake in the oven at 170°C (338°F) for 35-40 minutes.
Let cool completely and refrigerate.