Nature is clever. In the middle of winter, when everything is feeling grey and dreary, it offers up citrus. It's enough to just gaze upon the bright colours of lemons and oranges and limes and pink grapefruit and everything in between but the flavour of these fruits works the same way to shock you out of a slump.
This recipe requires a single bowl. If you don't have tangelos, oranges or lemons will do. Containing both oil and yoghurt, the cake keeps well which means you can make it ahead, or have it on hand for the week. But the colour! It's the best. Sweet and softly glowing, it's almost like eating sun.