Mix the flour, baking powder, salt and bicarbonate of soda together in a large bowl. Whisk the buttermilk, eggs and vanilla pod seeds in a separate bowl.
Cream the butter and sugar adding the butter milk gradually then adding the flour mix.
Blend until smooth (use a hand blender), then pour over the pineapple.
Bake for 35-40 minutes, allow to cool and serve in wedges.