- Preheat your oven to 170 degrees (for fan ovens) and line a cake or loaf tin with baking paper.
- Whisk the butter/coconut oil with the coconut sugar until light and fluffy, add the banana and continue to whisk on high speed until well combined.
- Add the eggs, carrot, sultanas and most of the orange juice and zest (reserve a little of each for the frosting) whilst mixing at a low speed.
- Add the spices, bicarb and flour and fold in until just combined, be careful not to overmix here.
- Pour into your baking tin, cover with additional baking paper to prevent the top from burning. Bake for 45-60 minutes until a skewer comes out clean.
- Remove from the oven and leave to cool completely.
- Combine the quark, honey and remaining orange juice/zest and use to ice the top of the cake.
You could also make this into a tray bake or cupcakes, just be sure to reduce the cooking time appropriately.