I had a completely different story in mind to go along with this cake.
It was about my fourth of July, and a barbecue in the rain, and sneaking into someone's lakeview backyard to catch the fireworks from the best possible standpoint. It was about how, sometimes, fun sneaks up on you in unexpected, unplanned for, sloppy ways.
However, things don't feel quite so festive a week later. Especially when that week has included torrential downpours that, while my car was parked ever so innocently at work, gathered in a deep flood in our crappy, half-gravel parking lot by the train tracks and seeped into my car. Yes, it flooded. No, it didn't happen to anyone else. Yes, this is the car I bought, brand new, just three months ago.

So it doesn't feel quite right to overlook this week's disaster and paint you a pretty picture about fireworks and cake. But it does feel alright to tell you how you will lose yourself in this cake when you're alone in your kitchen, peacefully making use of every aspect of the grapefruit. You'll zest the grapefruit peel, then
segment out the colorful fruit that's so juicy it's dripping. And then you'll squeeze the remaining pulp and membrane for the juices that will add sweet, tangy flavor to the cake. This is a good cake to get lost in and forget about your flooded car/ bad day at work/ brand new shirt that shrunk in the dryer/ [insert your woes here].

I did make this for that fourth of July barbecue, and it was actually a really big hit. Grapefruit in a cake is such a novel idea to me, and the flavor was very distinct: fresh and fruity with a tart little kick.
I used half the amount of cream cheese than was recommended, because, well, two packages of cream cheese just seems a little obscene for icing. One worked really well. If I were you, I would pick your favorite white cake recipe and incorporate the grapefruit juice into that, as I found the cake rather thick and dense. It works, especially with the slices of pink grapefruit sitting atop a thick layer of icing, but I'd much prefer a fluffier, moister cake. And maybe instead of lining the bottom with grapefruit slices... try slicing them smaller and mixing them right into the batter. Mmm. Try it your own way, will you, and let me know what happens?

Grapefruit Cake
3 pink grapefruits
2/3 cup butter, softened
3 cups flour
1 teaspoon baking powder
1 3/4 cup sugar, plus a little more
2 eggs
3/4 cup milk
1 1/2 teaspoon vanilla
1/2 pound (1 package) cream cheese, softened
2 1/2 - 3 cups confectioner's sugar
Begin by zesting one of the grapefruit to get 2 teaspoons of zest. Work a little sugar into the zest to bring out the flavor, then set the zest aside. Peel and segment the grapefruit into slices, making sure to avoid all of the bitter pith and the membrane. Set the segments aside. Squeeze juice from the remaining pulp, reserving 1/2 cup plus 1 teaspoon, and set aside.
Preheat oven to 350 degrees. Grease a 9 x 13'' baking dish with butter, and sprinkle lightly with flour.
In a bowl, whisk the flour and baking powder together. Set aside.
In a large bowl, cream together butter and sugar with an electric mixer. Beat in the eggs one at a time, until fluffy. Add the 1/2 of grapefruit juice, milk, and vanilla, and stir. Gradually add the flour mixture and stir until combined.
Line the bottom of the baking dish with half of the reserved grapefruit, then pour in the batter and smooth it down. Bake about 35-40 minutes, and let it cool.
In a large bowl, beat the cream cheese until fluffy. Add the reserved zest and remaining grapefruit juice and beat again. Add confectioner's sugar 1/2 cup at a time until you've reached the desired consistency. Smooth the icing over the cake, topping with the remaining segments of grapefruit. Chill before serving.