Preheat the oven to 175°C. Grease and flour a 20cm round springform baking tin. Sift the flour and bicarbonate of soda into a bowl. In a mixer, beat the sugar and butter until light and fluffy. Add the sugar and zest and beat for another 2 mins before adding 2 of the eggs one at a time. Then add half the flour followed by the buttermilk, the remaining flour and eggs and beat until smooth. Remove from the mixer and gently fold in the raspberries, pour into the baking tin and bake for 50 mins. Reduce the heat to 150°C and bake for a further 30 mins or until skewer comes out clean when inserted into the middle.
Allow to cool in the tin for 10 mins before turning out onto a rack.
Dust with icing sugar and serve with Pauls Dollop Cream and fresh raspberries.