I made this Smitten Kitchen Grapefruit Yogurt Cake over a month ago, and have been raving about it ever since. I actually got some more grapefruit over the break, and will be making more of this, pronto.
There is grapefruit zest in the cake itself, and juice in the two glaze mixtures on top. It's fantastic and tastes very clean/citrus-y. If grapefruit's not your thing, or it's not readily available, make it with orange, lemon, lime, or any other juicy fruit.
I wish you all a very HAPPY New Year!!