Citrus Surprise Grapefruit Cake: Surprise! It's 100% Whole Wheat!


Ah, the giddy days in the kitchen. You know the ones, where you suddenly see Al Pacino’s face in your morning toast, or you sing “Heard It Through the Grapevine” while measuring out your raisins (complete with hand rolls, if you lived through the ’80s). I’m prone to juggling oranges and lemons and, …

…when grapefruit is involved, I’ve been known to hold the fruit aloft in one hand, Hamlet-style, and wax poetic about knowing poor Yorick well.

Cue the eye-rolling and catcalls of “get off the stage!” from my teen, but I keep myself entertained. In these times when a gallon of milk outprices a gallon of gas, we all need as much laughter in our day as we can get.

So, were you surprised to see a recipe for a layer cake that’s 100% whole wheat? I know I was when I read the original recipe in our Whole Grains Baking book.

I fully expected the ingredient list to call for whole wheat pastry flour, the flour of choice for whole wheat pastries, but was pleasantly surprised to see that it called for our King Arthur White Whole Wheat Flour, a pantry staple in our kitchen.

This cake starts with a cloud of whipped egg whites that work to keep it light. Vegetable oil takes the place of butter, making this a classic chiffon cake. It’s really one of the easiest types of cakes to make, and yields an especially tender and light dessert.

Let’s make Citrus Surprise Grapefruit Cake.

Separate 5 large eggs carefully, setting the yolks aside and adding the whites to the bowl of your mixer. Be diligent about keeping the yolks out of the whites, as even a little yolk will affect how the whites whip up.

Beat the whites until they begin to foam, then add 1/4 teaspoon cream of tartar. Continue to whip until the whites are stiff, but not dry. “Billowy” is a good way to describe them at this stage.

Scrape the whites gently into a clean bowl, and set aside. You’ll use the same bowl to mix up the rest of the batter, so no need to wash it.

Grate 1 tablespoon peel from a fresh grapefruit; this grated peel is called “zest.” A spare cupcake paper makes a handy place to keep the zest.

Add the 5 egg yolks and 1/2 cup vegetable oil to the bowl, and beat at low speed. Slowly add  1 1/2 cups of sugar as the mixture thickens and turns lighter in color.

Add 1/3 cup water and 1/4 cup freshly squeezed grapefruit juice. That’s right, give Yorick a good squeeze in the head, and strain any seeds from the juice until you have 1/4 cup.

Beat the batter for 3 minutes on medium speed, then mix in the zest.

In a small bowl whisk together 2 cups King Arthur White Whole Wheat Flour, 2 teaspoons baking powder, and 1/2 teaspoon salt. Add this dry mixture to the batter and beat just until combined, about 30 seconds.

With a wide rubber spatula, fold the whipped egg whites into the cake batter in three stages. Fold just until a few streaks of white remain. Take care not to over-beat, as this will deflate the whites and make for a heavy cake.

Divide the batter evenly into two 9″ round pans that have  been greased and lined with parchment paper. Bake at 350°F for 20 to 25 minutes. A cake tester inserted into the center of one of the layers will come out clean, and the cake will begin to pull away from the sides of the pans.

Run a nylon spreader around the cake edges, and let cool in the pans for 10 minutes before turning out onto a wire rack to cool completely.

The original recipe calls for cream cheese icing laced with a little more grapefruit zest, but I’m on an Italian buttercream kick right now, so that’s what I chose.

You’ll need about 3 cups of prepared icing. Add 2 to 3 teaspoons of grapefruit zest to the icing, and a tablespoon of grapefruit juice, or to taste. I added 3 drops of pink food coloring and 1 drop of orange color to turn the icing a lovely pink grapefruit color.

To make a beveled top on the icing, ice the top of the cake as usual, then run the tip of an offset spatula across in stripes from right to left. Press the tip in slightly to create panels that appear to overlap as they cross the top of the cake.

You can do the same thing around the edge of the cake, always working in the same direction. If you’re feeling fancy, you can pipe on a border and add some colored sugars, too.

Again, I used a blend of pink and orange to give that pink grapefruit feel to the cake. By the end of the day I was feeling positively tropical!

Isn’t that a lovely slice of cake? Check out the tender crumb, the light color and texture.

Now be honest, was your first thought “whole wheat“? I’m going to guess not. This cake certainly didn’t last long on the tasting table and I’ve actually been craving it for the past week, so you know another is in the works. I guess I’d better polish up my Hamlet… To cake, or not to cake; it’s not really a question, now is it?

Please bake, rate and review our recipe for Citrus Surprise Grapefruit Cake.

Print just the recipe.

MaryJane Robbins

MaryJane Robbins grew up in Massachusetts and moved to Vermont 20 years ago. After teaching young children for 15 years, she changed careers and joined King Arthur Flour in 2005. MaryJane began working on King Arthur Flour's baker’s hotline in 2006, and the blog team ...


  1. Sandy

    This looks great for a hot summer’s day! And I’m so glad to see individual pics of the various stages, rather than those collage-style groupings. :)

    Sandy, the collage-style groupings help the blog post load faster, which is more critical on a mobile device than on a laptop – and mobile is growing SO fast, we have to accommodate. Did you know that when you click anywhere on the pictures, you can see them blown up nice and large? Maybe that will make them a little more palatable… :) PJH

  2. JuliaJ

    Does this work with lemons instead of grapefruit? I do plan on trying the grapefruit first as I have a grapefruit tree and it’s hard figuring out what to do with all the fruit. Thanks!

    Julia, I’d assume this would work just fine with lemon – and I’m sure it would be very tasty! PJH

  3. estrellas

    This is fantastic — looks so nice and light! Now if only i could figure out what “goes with” grapefruit! Do you have any serving suggestion, apart from just devouring it straight?

    I’d just devour it straight, truthfully; though a side of some sweetened grapefruit sections wouldn’t be amiss… PJH

  4. cupcake store

    it looks yummy. I hope it doesn’t have dry taste. you know I mean sometimes there is cake that is too dry for us to shallow.

    This is an American-style, moist cake as opposed to one of the drier, European-style cakes. Enjoy! PJH

  5. martibeth

    Not to be a stickler for correctly spelled words, but don’t you mean to say “Citrus Surprise Grapefruit Cake” in the headline?

    From one stickler to another – YUP!!! Thanks, Marti – PJH

  6. joltster

    Hi: this looks great, however, I don’t like grapefruit. Can this be done with lemon or orange & if so, how.
    Jackie JUlty
    Yes, lemon in place of grapefruit sounds really good. If you were to do orange, you may want to cut back on some of the sugar as oranges are sweeter. Cut back on the sugar by 3-4 T and see how it goes. Elisabeth

  7. bjmlorenz

    I love this cake and have made it several times since buying the whole grain book several years ago. I usually make it in a 13×9 pan, but it was fun to see your photos of it.
    That’s my only complaint with that book- not enough photos.

    Yes – color photos back then were SO expensive, they would have driven the price of the book up to astronomical levels, unfortunately… Glad you like the cake, though. PJH

  8. kathcdy

    Can this cake be made with whole wheat pastry flour or other substitutes?

    No, I would stick to white whole wheat for this recipe. WW pastry flour will not hold up the structure. Elisabeth

  9. daltstatt65

    This cake is beautiful, and a friend just gave us some huge grapefruit, which I was wondering what to do with! White whole wheat is extremely hard to find around here – can I just use regular whole wheat or regular white flour?
    If you use white flour, you may want to reduce the liquid amount by a few tablespoons. Using whole wheat flour would be fine, but know that it will make a difference in the flavor and texture of the cake. ~Amy

  10. glpruett

    This looks great, but I don’t have any grapefruit in the house right now, so I guess I’ll have to wait! What is that about PATIENCE being a virtue?!?

    I do have a comment, though, about the Italian Buttercream. I’ve made it many times, and absolutely love the smooth, barely-sweet delicate topping it gives cakes, cupcakes, and cookies of many kinds. Recently, though, I’ve discovered an incredible “short-cut”, thanks to Karen Tack and Alan Richardson’s new “cupcakes, cookies & pie, oh my!” cookbook, the third in their famed cupcake series.

    Okay…get ready…Marshmallow Fluff to the (time-crunched) rescue! Tack and Richardson’s “Almost-Homemade Vanilla Buttercream” recipe is ingenious…you beat 3 sticks (1 1/2 cups) of soft, unsalted butter, cut into 1″ pieces, in a stand mixer at medium speed until light and fluffy. Then beat in one 16-ounce container of Marshmallow Fluff, beating until smooth, scraping down the sides of the bowl as necessary. Add 1/2 cup of confectioners’ sugar and 1teaspoon of vanilla and beat until light and fluffy. To make a cocoa version, simply add 3 tablespoons of dry cocoa powder with the confectioners’ sugar.

    I didn’t believe it when I first got their new book, but I decided to give it a whirl and…IT WORKS! It honestly tastes incredibly like Italian Buttercream, which makes perfect sense because to make Italian Buttercream, you basically cook a sugar syrup, pour it over egg whites, and what, after all, is a marshmallow anyway? Sugar syrup poured over egg whites!

    My suggestion is to try it…you can have a very, very good buttercream ready to go in a jiffy, as opposed to the rather lengthy process of making Italian Buttercream from scratch.

    What a super idea! I’ve just copied this to a Word document and printed it for my home recipe files… Thanks! Would this be enough for, what, a double-layer cake, or 24 cupcakes, something in that range? I’m not a big cake baker, but am always looking for easy, time-saving tricks. PJH

  11. glpruett

    Glad you like the idea, PJ! It makes about 3 1/2 cups of frosting. I recently frosted two dozen cupcakes with it, using a large star tip with a swirl pattern and I had a little over a cup left over. I froze the leftovers, hoping that it will defrost and rewhip as well as Italian Buttercream does. I haven’t had any reason to use it yet, so it remains stashed in my freezer. I’ll let you know how it works from the frozen state!

  12. glpruett

    Great news, PJ! I thawed my Marshmallow Fluff version of buttercream today, and it DOES whip well and frosts and tastes just as good as when it was fresh! I’m so glad I’ve discovered this trick!

    I’ve got this printed out – next b-day cake, I’m trying it. Thanks again! PJH


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