The Best Grapefruit Cake

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Buttery grapefruit cake takes a delicate cake filled with fresh grapefruit zest and simple syrup and tops it with a grapefruit glaze for the perfect sweet and tart cake.

A loaf of grapefruit cake on a blue platter with three grapefruit slices on top.

Last week I got an amazing box of produce from Melissa’s Produce.  Inside were several different types of citrus fruits which were calling my name.  I’ve been on a huge sweet and tart kick the last month so I immediately started thinking about what I could make.

While grapefruit is not my favorite fruit I couldn’t stop thinking about the gigantic grapefruit in my box.  My son kept call it the “big orange” which cracked me up. 

I had it in my head that I wanted to make either grapefruit bread or grapefruit pound cake and after looking around I made a combination of both.  The Best Grapefruit Cake is a sweet cake that has a delicate crumb and a tartness that comes from homemade grapefruit simple syrup.


  • flour
  • baking powder
  • salt
  • butter
  • sugar
  • eggs
  • sour cream
  • grapefruit zest
  • vanilla
  • fresh squeezed grapefruit juice
  • powdered sugar

The recipe is fairly easy to make.  The dry ingredients are mixed in one bowl while the wet ingredients are mixed in another.  The two are combined and the cake goes into a loaf pan and into the oven.

Pin Image: A loaf of grapefruit cake with three grapefruit wedges on top on a blue platter, text, a cutting board with sour cream, eggs, flour, a grapefruit, and butter on it.

While the cake is baking I made the grapefruit simple syrup.  To do this I simply heated the fresh squeezed grapefruit juice and the sugar and brought it to a boil.

Once the cake came out of the oven I poked some holes in the top and poured the simple syrup all over it.   After a few minutes it soaked it and I added some more until my syrup was gone. 

I got the cake out of the pan and added a few fresh grapefruit slices to the top and it was really gorgeous.   The syrup added a nice shine to the top and the color of the grapefruit was beautiful.

As an afterthought I added a grapefruit glaze but you can totally make this without it.   The inside is soft and moist from the grapefruit syrup while the outside of the cake is golden brown and firm.  It’s the perfect combination of sweet and tart and is great as an afternoon snack with a glass of milk or as dessert with a cup of coffee.

A loaf of grapefruit cake on a blue platter with three slices of grapefruit on top and a piece of the cake sliced off.

Pro Tips and Substitutions:

  • If you aren’t a huge fan of grapefruit you can make this with oranges instead.  You could also do a combination of grapefruit and oranges.
  • Out of sour cream?   Use plain or vanilla yogurt in place of it.
  • If you are looking for a sweeter cake you can put a grapefruit cream cheese frosting on top which is amazing.  Just add grapefruit juice in place of the milk in a cream cheese frosting recipe.

If you’ve tried my The Best Grapefruit Cake or any other recipe on Hezzi-D’s Books and Cooks please take a minute to rate the recipe and leave a comment letting me know how you liked it. I love hearing from you! You can FOLLOW ME on:

A loaf of grapefruit cake on a blue platter with three grapefruit slices on top.

The Best Grapefruit Cake

Buttery grapefruit cake takes a delicate cake filled with fresh grapefruit zest and simple syrup and tops it with a grapefruit glaze for the perfect sweet and tart cake.
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Prep Time: 20 minutes
Cook Time: 50 minutes
Total Time: 1 hour 10 minutes
Calories: 165kcal
Author: Hezzi-D


For the cake:

  • 1 1/2 c. flour
  • 2 teaspoons baking powder
  • 1 teaspoon salt
  • 1 stick 1/2 c. butter
  • 1 c. sugar
  • 3 eggs
  • 1 c. sour cream
  • 2 teaspoons grapefruit zest
  • 1 teaspoon vanilla

For the simple syrup:

  • 1/3 c. freshly squeezed grapefruit juice
  • 1/3 c. sugar

For the glaze:

  • 1/2 c. powdered sugar
  • 2 Tablespoon fresh squeezed grapefruit juice


  • Preheat the oven to 35o degrees.
  • Spray a loaf pan with cooking spray and set aside.
  • In a small bowl combine the flour, baking powder, and salt.
  • In a large bowl cream together the butter and sugar.
  • Add in the eggs and mix until well combined.
  • Add in the sour cream, grapefruit zest, and vanilla. Mix well.
  • Pour the flour mixture into the butter and sugar mixture and mix until well combined.
  • Pour the batter into the prepared pan and bake for 50 minutes or until golden brown and a toothpick inserted into the center comes out clean.
  • While the cake is baking make the simple syrup by combining the sugar and grapefruit juice in a small pan over medium high heat.
  • Bring the syrup to a boil and heat for 1 minute, stirring constantly. Remove from heaat.
  • Once the cake comes out of the oven put the loaf pan on top of a wire cooling rack. Poke holes about an inch deep in the cake.
  • Pour half of the simple syrup over top of the cake and spread it around until it soaks in.
  • Run a butter knife around the edges of the pan and turn the cake out onto the wire rack.
  • Turn the cake right side up and then pour the remaining simple syrup on top and spread it around.
  • Allow the cake to cool completely then place several thin slices of grapefruit on top.
  • To make the glaze whisk together the grapefruit juice and powdered sugar. Drizzle over top of the cake and slice to serve.


Recipe adapted from Life is but a Dish


Serving: 1g | Calories: 165kcal | Carbohydrates: 31g | Protein: 3g | Fat: 4g | Saturated Fat: 2g | Polyunsaturated Fat: 1g | Cholesterol: 43mg | Sodium: 211mg | Sugar: 21g
Grapefruit cake in a loaf pan with half a grapefruit in the background.


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