This cake can be made with whatever citrus you have on hand. Grapefruit would be delicious paired with orange. Blood orange will be lovely when they’re in season later this year.

If you don’t have a 9” cake pan, you can use a 1 1/2 pound loaf pan (baking time will be ~15-20 minutes longer). I’d caution against using an 8” pan as the cake nearly fills the 9” size pan.