This Grapefruit Sour Cream Cake is deliciously moist, bursting with bright citrus flavor and coated in a thick layer of sour cream icing. Yield 8 to 10 slices.

Grapefruit Sour Cream Cake

I’m not a huge dessert person, but when faced with a decision of chocolate or lemon (any citrus really), I’ll chose lemon every single time. Years ago I was gifted a box of ruby red grapefruits I had a little time before delivery to figure out what I was going to make using them.

The obvious answer was cake.

So I took inspiration from this lemon blueberry cake recipe and the technique from this mini cake recipe, did a little ingredient swap and this beautiful cake was born.

Grapefruit Sour Cream Cake

It’s citrusy, tangy, and in a way tastes like froot loops cereal – but in the best way. Because cake.

Ingredients for Grapefruit Sour Cream Cake

To Make The Grapefruit Sour Cream Cake You Will Need:

  • unbleached all-purpose flourGives structure to the cake.
  • fine salt Enhances the flavor of the cake.
  • baking powderWill create lightness in the batter, which in turn, makes it rise.
  • granulate sugar (white) – For sweetening and flavor.
  • grapefruit zest and juiceLends tart citrus flavor.
  • eggsActs as a binding agent, helps the cake rise and adds rich flavor.
  • unsalted butter (melted and cooled) – Adds moisture, richness and flavor.
  • sour creamLends moisture and tangy rich flavor.
  • milkAdds moisture to the cake. Use any milk you prefer.

for the icing:

  • powdered sugar
  • sour cream
  • milk

preheat oven and line and spray pan

Preheat your oven to 350℉ (or 180℃).

Line a 8×5 loaf pan with parchment and spray with a nonstick baking spray.

whisk dry ingredients

Make The Cake:

In a medium bowl, measure and add 1-1/2 cups flour, 1 teaspoon fine salt and 1 teaspoon baking powder. Give that a whisk and set it off to the side.

rub sugar and zest together

In a large bowl, measure and add 1 cup of sugar and the zest of 1 ruby red grapefruit. Use your fingers and rub the sugar into the zest until the texture feels like wet sand.

add butter, eggs to sugar mixture

Next, add in 2 large eggs, 3 tablespoons grapefruit juice and 1/3 cup melted (and cooled) butter.

whisk to combine

Whisk well to combine.

combine milk and sour cream

Next, in a small bowl or measuring cup stir together 1/2 cup of sour cream and the 2 tablespoons of milk. Doing this makes adding to the batter more simple.

alternate adding dry ingredients

Beginning with the dry ingredients and ending with the sour cream mixture, alternate adding 1/3 of the dry ingredients and stirring just until combined.

and sour cream mixture

Then add in 1/3 of the sour cream mixture, repeating until it’s all incorporated.

transfer to prepared pan and smooth out

Pour the cake batter into a lined loaf pan and spread the top smooth. Bake in a preheated oven for 45 minutes or until a tester comes out clean. Do NOT over bake!

just baked Grapefruit Sour Cream Cake

Let the cake cool in the pan for 10-15 minutes before removing and transferring to a wire rack to finish cooling.

whisk glaze ingredients

Make The Icing:

Into a medium bowl, sift 1-1/2 cups powdered sugar. Whisk in the sour cream while thinning it out with 2-3 tablespoons of milk at a time. You want it thick but pourable.

pour over cake

Then drizzle it all over the cooled cake. Allow the icing to set before serving. You can pop it into the fridge to speed the process up a bit.

Grapefruit Sour Cream Cake


Grapefruit Sour Cream Cake

Serve. And prepare yourself to fall in love!

Grapefruit Sour Cream Cake

How to Store Grapefruit Sour Cream Cake:

Transfer slices of the frosted cake to a storage container and refrigerate.

How To Freeze Grapefruit Sour Cream Cake:

Double wrap the unfrosted loaf in plastic wrap and then in aluminum foil. Thaw when ready to serve. Once the loaf has thawed, is when I  would recommend make the icing and drizzle it over the cake.

How Long Will This Grapefruit Sour Cream Last?

If stored properly, this cake will last up to 3 to 4 days if refrigerated and at room temperature or freeze for up to 3 months.

Grapefruit Sour Cream Cake

Grapefruit Sour Cream Cake
Print Recipe Pin Recipe
No ratings yet
Leave a Review »
Yield: 10 servings

Grapefruit Sour Cream Cake

This Grapefruit Sour Cream Cake is deliciously moist, bursting with bright citrus flavor and coated in a thick layer of sour cream icing. Yield 8 to 10 slices.



  • cup unbleached all-purpose flour
  • 1 teaspoon fine salt
  • 1 teaspoon baking powder
  • 1 cup granulated sugar
  • 1 grapefruit zest, zested
  • 1/3 cup unsalted butter, melted and cooled slightly
  • 2 large eggs
  • 3 tablespoons grapefruit juice, freshly squeezed and strained
  • 1/2 cup sour cream
  • 2 tablespoons milk


  • cup powdered sugar
  • 1 tablespoon sour cream
  • 2 to 3 tablespoons milk



  • Preheat your oven to 350℉ (or 180℃) and line an 8x5 loaf pan with parchment paper, then spray with cooking spray (I use one that contains flour).
  • In a separate bowl, combine the flour, salt and baking powder. Whisk to combine.
  • In a large bowl combine the sugar and grapefruit zest. Use your fingers and rub the zest into the sugar until it resembles wet sand. Add the eggs, grapefruit juice and melted butter. Stir until those ingredients are incorporated.
  • In a small bowl or measuring cup; combine the sour cream and milk and stir until combined.
  • Starting with the flour and ending with sour cream/ milk mixture. Alternate adding 1/3 of each to the grapefruit mixture, mixing after each addition, until everything is incorporated.
  • Pour the cake batter into the prepared pan and bake for 45 minutes or until a tester comes out clean. Let the cake rest in the pan for 10 minutes before using the parchment paper to lift the cake out of the pan.
    NOTE: If the cake sticks at all, try running a knife along the edge of the cake before lifting.
  • Let the cake cool completely on a wire rack.


  • In a medium bowl, sift the powdered sugar. Then whisk in the sour cream and while thinning it out with a little milk at a time. You want it thick but pourable.
  • Drizzle the glaze over the cooled cake and let it sit to harden for a few minutes. You can pop it into the fridge to speed the process up a bit.
Serving: 1slice, Calories: 315kcal, Carbohydrates: 54g, Protein: 4g, Fat: 10g, Saturated Fat: 6g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 3g, Trans Fat: 0.3g, Cholesterol: 62mg, Sodium: 297mg, Potassium: 70mg, Fiber: 1g, Sugar: 39g, Vitamin A: 333IU, Vitamin C: 2mg, Calcium: 56mg, Iron: 1mg