Preheat the oven to 180 C / Gas 4. Butter 8 mini cake tins. Whisk together the plain flour, baking powder, caster sugar and salt in a bowl.
Beat the eggs, olive oil and milk together in a large bowl. Stir in the flour mixture gradually, just until all ingredients are moistened. Stir in the chopped pear and chocolate chips. Divide the cake mixture into the prepared mini cake tins.
Bake in the preheated oven until a skewer inserted near the centre comes out clean, about 20 minutes. Cool in the tins for 5 minutes before turning out onto a wire rack to cool completely.