Grapefruits aren't to everyone's liking and the same can be said for this cake. It's a lovely moist cake that looks stunning, but it's made with whole grapefruits and retains a little bit of the bitterness of the fruit.
If you like your sweets not-so-sweet then give it a go. If you prefer something a little less risky, just swap the grapefruit for oranges and use a little less sugar. This cake is also gluten free, which is great if you're baking for anyone who can't handle flour.
Cake 2 grapefruits
250g caster sugar (215g if making an orange cake)
300g almond meal
1 tsp gluten free baking powder
Place sugar and water for the syrup in a pot with the sliced vanilla bean over medium heat. Stir until the sugar has dissolved, then add the slices of grapefruit making sure they're covered. Cook for 15 minutes.
Meanwhile grease your cake tin with butter.
Remove the grapefruit slices from the syrup and use them to line the bottom of the cake tin. Remove the vanilla bean pod and keep the syrup aside for later.
Preheat the oven to 170 degrees C.
Add grapefruit to a pan of cold water and boil, cooking then for 15 minutes.
Rinse grapefruit and then repeat. This helps remove some of the bitterness from the grapefruit.
Roughly chop and then process in a food processor until smooth.
Beat sugar and eggs in a stand mixer until creamy. Fold in grapefruit, flour and baking powder, then add to the cake pan over the grapefruit slices. Cook in the oven for 1 hour.
Remove the cake from the oven and turn it upside down. Gently remove the base of the pan, and rearrange any grapefruit slices that may come off.
Add the grapefruit juice to the leftover syrup and cook over a low heat until the syrup thickens. Pour the syrup over the cake before serving.
The cake goes great with some whipped plain cream. Don't add too much sugar. The cream will also help balance out a bit of the bitterness.