210g Plain Flour
2/12tsp Baking Powder
1 Pinch Salt
3/4 Cup Buttermilk
1/4 Cup Milk
227g Unsalted Butter
300g Caster Sugar
2 Large Eggs
1tsp Vanilla Extract
For the Chocolate Marbling:
1tbsp Caster Sugar
1tbsp Melted Butter
30g Cocoa Powder
1/8tsp Baking Powder
1. To begin, place the flour, cornstarch, baking powder and salt into a large mixing bowl and combine.
2. In a separate bowl/jug, whisk together the buttermilk and milk. Set aside.
3. In another bowl, beat the butter for a few minutes until soft and light, and then add the sugar. Continue beating (preferably with an electric mixer) for a further few minutes until the mixture is pale, light and creamy,
4. Gradually add the eggs, one at a time, and beat well to combine. Add the vanilla and ensure it is well incorporated.
5. Add half of the flour and use a spatula to gently fold it in. Next, add half of the buttermilk/milk mixture and continue to fold in. Finish off with the remaining flour and then the remaining buttermilk. Stir until just combined but don't overmix.
6. Remove a cup full of the cake mixture and set aside for the chocolate marbling.
7. For the marbling, place the milk, butter and sugar in a saucepan and gently heat. Stir to dissolve the sugar and then add the cocoa powder. Whisk to remove any lumps and then add the baking soda. Add one or two spoonfuls of the cake batter to this mix and stir to combine. Add the remaining batter and fold until well incorporated.
8. To assemble the cake, generously butter your bundt tin and dust with flour (shaking off any excess. Pour in 2/3 of the vanilla cake batter and using a teaspoon, create a small well in the centre of the batter running all the way around the tin. Pour the chocolate mix into this well and, using the end of a knife, ripple the chocolate through the mix. Top with the remaining vanilla batter and swirl again with the knife.
9. Place the cake into a preheated oven at 180 degrees for 45 minutes or until a skewer comes out clean. Allow to cool in the pan for 10 minutes before turning the bundt out onto a cooling rack.
10. Serve with a dusting of icing sugar and a mug of hot tea!