Boil Pimms, vanilla pod, and sugar in a pan for 6 to 8 minutes until a syrup forms.
Cool the syrup slightly and pour it over the strawberries, kiwi, raspberries, and blueberries in a bowl.
Preheat your oven to 165°C.
Sift flour, baking powder, sugar, and salt into a large mixing bowl.
Beat the butter in a separate bowl and incorporate eggs one at a time.
Mix in the vanilla seeds and lemon zest.
Blend in the buttermilk and fold the wet mixture into the dry flour mixture.
Pour the batter into a greased and lined 22cm springform cake tin.
Bake for 1.5 hours until golden-brown and a skewer comes out clean.
Cool the cake in the tin briefly before transferring to a cooling rack.
Serve cake wedges with clotted cream and the Pimms-soaked fruit.