Grapefruit Sheet Cake
My memorial day contribution
I had a bowl of grapefruits staring at me for weeks from the counter and a vision of a bright, airy citrus sheet cake for Memorial Day.
Naturally, things got complicated.
I started with a plan: a fluffy grapefruit cake with whipped egg whites, a citrus soak, and a cloud-like frosting. Then I realized I didn’t have enough avocado oil. Then I used half yogurt and half sour cream. Then my cake flour was expired. Then I became convinced the batter was too small for the pan.
By the time the cake was in the oven, I was certain I’d made a mistake.
But that’s the thing about simple cakes: they often look unimpressive right until they don’t.
What came out of the oven was actually a masterpiece. The crumb stayed soft and airy, the citrus brightened overnight, and after an unsuccessful attempt at making cream cheese frosting, I dusted it with powdered sugar and topped it with fresh mint.
And suddenly it became exactly what it wanted to be, a simple grapefruit cake. A snacking cake if you will.
Ingredients
238g all-purpose flour
36g cornstarch
homemade cake flour mixture
2 tsp baking powder
1/2 tsp baking soda
1/2 tsp salt
300g sugar
Zest of 2 grapefruits
2 eggs, separated
120g Greek yogurt (or use all greek, or all sourcream)
120g sour cream
65ml avocado oil
55ml olive oil (or use all avocado oil)
180ml fresh grapefruit juice
30ml milk
1 tsp vanilla
Grapefruit Soak
60ml grapefruit juice
1–2 tbsp sugar
To Finish
Powdered sugar
Fresh mint
Grapefruit zest (optional)
Instructions
Preheat oven to 350. Grease and line an 9x13-inch baking pan with parchment paper.
Whisk together the flour and cornstarch. Add baking powder, baking soda, and salt.
In a large bowl, rub the grapefruit zest into the sugar until fragrant.
Add egg yolks, yogurt, sour cream, oils, grapefruit juice, milk, and vanilla. Whisk until smooth. Fold dry ingredients into the wet ingredients until just combined.
In a separate bowl, whip the egg whites to soft peaks.
Gently fold the egg whites into the batter in two additions.
Pour into the prepared pan and smooth the top.
Bake for 26–32 minutes, or until the center springs back lightly and a toothpick comes out with a few moist crumbs.
While the cake bakes, warm the grapefruit juice and sugar until dissolved.
Poke small holes over the warm cake and brush the grapefruit soak evenly across the surface.
Let cool completely. Dust generously with powdered sugar. Garnish with fresh mint and grapefruit zest before serving and enjoy!!