1.Split vanilla bean lengthways; scrape seeds into a large saucepan. Add vanilla bean, caster sugar and 3 cups water and stir over low heat until sugar dissolves. Add pears; bring to the boil.
2.Reduce heat. Simmer with lid off for 10 minutes, turning halfway through cooking, or until pears are tender. Remove from heat and add two-thirds of the raspberries. Allow to stand 30 minutes.
3.Using a slotted spoon, remove pears from syrup and cut in half lengthways. Bring syrup to the boil and boil 20 minutes or until thick and syrupy. Add remaining raspberries.
4.Preheat oven to 180°C. Grease six ¾-cup (180ml) square or round pie tins and line base and sides with baking paper.
5.Beat butter and sugar in a small bowl with an electric mixer until light and fluffy. Beat in eggs, one at a time. Stir in sifted dry ingredients and 1 tbsp water. Spoon mixture into tins; stand two pear halves upright in each tin.
6.Bake cakes 25 minutes or until firm to the touch. Serve cakes drizzled with reserved syrup and raspberries.