Preheat oven to 190 C / Gas 5. Line a baking tray with baking paper.
Beat butter, sugar and persimmon pulp together in a large bowl with an electric mixer until light and fluffy; beat in the egg and vanilla extract. Sift flour, bicarbonate of soda and salt together in a bowl; add gradually to persimmon mixture until dough is thoroughly combined. Stir in chocolate chips. Drop spoonfuls of dough 2cm apart on the lined baking trays.
Bake in the preheated oven until edges are golden, 10 to 13 minutes. Cool on the baking tray for 1 minute before removing to a wire rack to cool completely.
These cookies will not spread and only grow a little in the oven, so the shape and size you spoon onto the tray will be the same shape when cooked. This dough is sticky but you can smooth out the top of each cookie with a little water.