Brush a loaf tin (24 cm x 13 cm x 6 cm) with oil and line with baking paper.
Mix the flour, almond meal, baking powder and salt in a bowl and set aside.
In an electric mixer, blend the eggs and sugar until pale and creamy.
Add the ricotta and mix until there are no lumps remaining.
Mix in the oil, persimmon puree, orange zest and grand marnier.
Mix in the dry ingredients.
Pour into the prepared loaf tin. Bake for 50 to 60 minutes until a skewer inserted come out clean.
Rest in the tin for about 10 minutes before turning out onto a wire rack. Allow to cool completely before cutting. Decorate it with persimmon slices or dust with icing sugar.
Notes
Sometimes I divided the mixture in half and bake two smaller cakes. in this case, reduce the cooking time to about 40 minutes.