Last week, Will sent me flowers for no reason. So this weekend, I made him a cake for no reason (other than the fact I was reciprocating). As far as I’m concerned, making someone a cake is one of the loudest ways to say “I love you” with your clothes on. Even though it required hauling the Kitchen Aide down from the storage cabinet, deepening my forehead furrow to concentrate on leveling cake layers and donning buttercream freckles–courtesy of a broken whisk attachment–making this cake turned out to be really fun. Plus, there’s an inimitable satisfaction that hits you when stand back and look at your sweet masterpiece. If you’re feeling intimidated, don’t be. This recipe is just as tasty and the gesture is just as kind if you make it into cupcakes or a sheet cake.
Also, get excited, because I experimented (successfully!) with one (major!) shortcut; instead of doing from-scratch cake AND from-scratch buttercream, I enlisted help from my friend Duncan Hines. I disguised Duncan’s white cake mix (and took advantage of winter citrus) by adding a zing of pink grapefruit to the batter and frosting. The grapefruit flavor is subtle, but it’s there and it gave the cake a wonderfully delicate tang that reminded me of sherbert. This cake is perfect for a lemon-lover looking to date another citrus fruit.
Tips for making layer cakes:
- “Level” the cake tops by trimming the rounded top flat; it makes building the cake so much easier.
- If the buttercream breaks (it will look like thin, goopy cottage cheese) whisk it at high speed for 1-3 minutes. If you’re nearing the 3-minute mark and it’s still broken, whisk in a bit more powdered sugar and and it should come together.
- If you’re going to frost the whole thing (which, BTW, isn’t necessary; I love layer cakes with naked sides!), do it right. Give the entire stack (sides and all) a thin veil of frosting and refrigerate for 30 minutes. This “crumb coat” will make the final layer of frosting easier to spread.
- The buttercream can be made in advance and stored in the refrigerator for up to 3 days. Soften from the refrigerator by whisking it on high speed.
This recipe calls for grapefruit juice and zest. I juiced and zested 4 grapefruits and had plenty of juice both for the cake batter and the buttercream recipes.
Grapefruit Cake with Grapefruit Buttercream
For the cake…
- 1 box of Duncan Hines White Cake mix
- 1 cup of grapefruit juice
- Zest from 2 grapefruits
Prepare the cake mix according to package directions, except substitute 1 cup of freshly squeezed grapefruit juice for the 1 cup of water. Stir the zest into the batter just before you pour it into the cake pans. Bake according to package directions and cool completely.
For the buttercream…
- 1 1/2 cups of grapefruit juice
- 2 sticks of butter, softened
- 1 teaspoon of salt
- 4 cups of powdered sugar
- Zest from 2 grapefruits
While the cake is baking, pour the 1 1/2 cups of grapefruit juice into a small saucepan and bring to a simmer. Let simmer until the juice has reduced by half (about 20 minutes). It will taste like a Sweet Tart. Let the reduced juice cool completely.
In a stand mixer fitted with a whisk attachment, whisk together the butter and salt. Slowly incorporate the powdered sugar and reduced grapefruit juice, alternating between 1 cup of sugar and 1/4 cup of grapefruit juice, starting and ending with the sugar. Whisk in the zest. Use immediately or refrigerate for up to 3 days.
Here’s a nice primer on stacking and frosting a layer cake. Step #6 seems ambitious (hey, it’s Martha). Again, if you don’t feel like stacking or frosting anything, don’t worry. Cutting chunks of cake out of the pan and dunking them into the buttercream is always an option.