First, build and light a small campfire. You want to be able to bake this cake over hot embers and coals. Always check for fire restrictions in your area and practice fire safety at all times.
Line your dutch oven with baking paper and grease the bottom and sides of the pan with butter to ensure the cake doesn't stick.
In a large bowl, beat the butter and sugar together until they are pale and creamy.
Add eggs to the butter and sugar, one at a time, beating well after each addition.
Add in the vanilla and continue mixing for a further minute.
In a medium sized bowl, sieve together the flour, baking powder, kawakawa berry and salt.
Fold the flour mixture and sour cream into the egg and butter mixture. Do this in stages e.g one third at a time, until everything is incorporated together.
Place the lid of your dutch oven over hot coals to preheat it for 5 to 10 minutes while you finish preparing your cake.
Add in the lemon zest and half the blueberries to the cake batter. Fold together to evenly distribute the berries and zest then spread cake batter evenly into the prepared dutch oven.
Slice your strawberries in half and arrange them around the top of the cake. Scatter the remaining blueberries in between the strawberries then gently press the fruit into the batter.
Sprinkle the demerara sugar over the top of the fruit.
Place the dutch oven over your prepared coals and embers. Place the preheated lid onto and your dutch oven. Place a few scoops of hot coals on top of the lid of the dutch oven. This will allow the cake to cook evenly from the top and bottom.
Note: This recipe can also be made using a traditional oven. To bake this using your oven at home, preheat your oven to 170C fan bake. When you have prepared your batter into your dutch oven or bakingpan, place it into the oven without a lid and bake for 30 to 40 minutes.
After 30 to 35 minutes of baking, the cake should be ready. To test if the cake is done, remove the lid and insert a toothpick or skewer into the cake. It should come out clean when removed from the cake.
Once your cake is cooked, allow it to rest for 10 minutes before serving.
To serve, lightly dust with icing sugar and enjoywith fresh berries and the Kapiti Marlborough Salted Caramel ice cream. The cake and ice cream together are a truly beautiful match.