Cream the butter and sugar together until very pale in colour and fluffy in texture.
Beat in the vanilla extract and chocolate.
Beat in the eggs one by one.
Sieve in the flour and stir in alternately with the yogurt.
Cut the persimmon in half and scoop out the flesh. Stir into the cake batter.
Divide the mixture between two 12 hole mini muffin tins or cases. Bake at 180°C for 15-20 minutes, when the cakes should be risen and a skewer inserted comes out clean. Turn out onto a wire rack to cool.
Melt the white chocolate in a bowl over hot water.
Stir the vanilla paste into the mascarpone, then mix in the chocolate.
Spread the topping over the cakes and decorate as you wish (I used chocolate hearts).
Notes
Please note: calories and other nutritional information are per serving. They're approximate and will depend on serving size and exact ingredients used.