Coconut Rhubarb Breakfast Cake

Last updated on June 5th, 2025

Moist, tender and packed with jammy bits of sweetly tart rhubarb, this whole wheat Coconut Rhubarb Breakfast Cake is a simple take on a wholesome classic that features chewy coconut for a slightly tropical vibe.

This cake is everything I want in an early summer bake. A simple ingredient list that combines wholesome pantry staples with fragrant vanilla, pops of colour, naturally tart fresh rhubarb and buttery sweet, nutty coconut.

Here’s everything you’ll need to make it

• 2 cups (260 grams) whole wheat flour (either all-purpose or finely ground)
• 2 teaspoons (12 grams) baking powder
• 1 teaspoon (3 grams) kosher or fine sea salt
• 2 cups (200 grams) diced fresh or frozen rhubarb (*see note below)
• ½ cup (120 grams) butter, softened to room temperature (sub dairy free)
• 1 cup (200 grams) + 1 teaspoon (4 grams) granulated sugar, divided
• 1 egg, room temperature
• 1½ teaspoons (7 grams) vanilla 
• ½ cup (120 grams) buttermilk, room temperature (see note below to make your own)
• 2 tablespoons (12 grams) shredded coconut (I’ve used unsweetened but sweetened will work too) 

This two-bowl recipe starts with the dry ingredients in one and all the wet ingredients except the buttermilk in another.

Next, the rhubarb is tossed together with the flour mixture in step 2. This helps to soak up any excess moisture and ensures the pieces are evenly distributed and retain their shape.

Then the wet and dry ingredients are combined in stages together with the buttermilk. Lastly, the delicate, shredded coconut is folded in at the end to prevent over-mixing.

Tips for making this breakfast cake recipe

To make it gluten free: Use an equal amount of your favourite good quality 1:1 gluten free flour blend.

If using frozen rhubarb: Simply toss frozen rhubarb into the flour mixture straight from frozen. Do not thaw. If preparing the batter ahead of time, wait to add the frozen rhubarb until just before you’re ready to bake.

Make your own buttermilk: Add 2 teaspoons vinegar or lemon juice per ½ cup 2% or whole milk and let stand for 5 minutes while you mix together your remaining ingredients.

More reasons to love this Coconut Rhubarb Breakfast Cake

1. It’s moist and flavourful—the texture is gorgeous!
2. It’s made with buttermilk, which is rich in nutrients and healthy fats and can be easier to digest than other dairy products.
3. The coconut! It adds a slight chewiness to the texture and provides a lovely, sweet contrast to the rhubarb.
4. The batter can be made ahead of time and stored covered in the refrigerator overnight for a quick morning bake.
5. It’s freezer-friendly. You can even slice then stash this cake away in the freezer to enjoy later in the year!

Fantastic still warm, fresh from the oven, I sometimes think this Coconut Rhubarb Breakfast Cake is even better reheated with a little butter!

Try this Buttermilk Blueberry Breakfast Cake or this Lemon Blueberry Quick Bread next.

If you make this recipe, please tag me on Pinterest or Instagram so I can see! 

And of course, feel free to leave any questions, comments or reviews. This is the best place to reach me, and I’d love to hear from you!

Coconut Rhubarb Breakfast Cake

This cake is everything I want in an early summer bake. A simple ingredient list that combines wholesome pantry staples with fragrant vanilla, pops of colour, naturally tart fresh rhubarb and buttery sweet, nutty coconut for a slightly tropical vibe.

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Prep Time:20 minutes mins

Cook Time:45 minutes mins

Course: Breakfast, Dessert, Snack

Keyword: baking, breakfast cake, buttermilk, cake, rhubarb

Servings: 9

Equipment

• Mixing bowl set
• Measuring set
• 8-inch (2 Qt) glass baking dish
• Wire cooling rack

Ingredients

• 2 cups whole wheat flour either all-purpose or finely ground
• 2 teaspoons baking powder
• 1 teaspoon kosher or fine sea salt
• 2 cups diced fresh or frozen rhubarb see note below
• ½ cup butter, softened to room temperature sub dairy free
• 1 cup granulated sugar + 1 teaspoon (4 g), divided
• 1 egg, room temperature
• 1½ teaspoons vanilla
• ½ cup buttermilk, room temperature see note below to make your own
• 2 tablespoons shredded coconut I’ve used unsweetened but sweetened will work too

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Instructions

• Preheat oven to 350ºF (177ºC) and prepare a buttered or parchment-lined 8-inch baking dish.
• In a medium-sized mixing bowl, stir together flour, baking powder and salt. Fold rhubarb pieces into flour mixture just until they’re flour-covered and well distributed. Set aside.
• In a large bowl, cream together butter and sugar. Whisk in egg and vanilla.
• Add half the flour and rhubarb mixture to the wet ingredients and stir. Pour in butter milk and continue to mix until well combined. Stir in remaining flour and rhubarb and mix just until the batter is nice and thick and the rhubarb is evenly distributed, then add the shredded coconut and stir one last time.
• Spread batter into prepared pan and sprinkle the remaining teaspoon of sugar across the top. Bake for 45 minutes on the middle rack until golden and a tester comes out clean.
• Remove from oven and let cool on a wire cooling rack for at least 20 minutes before slicing.

Notes

To make gluten free: Use an equal amount of your favourite good quality 1:1 gluten free flour blend.

If using frozen rhubarb: Simply toss frozen rhubarb into the flour mixture straight from frozen. Do not thaw. If preparing the batter ahead of time, wait to add the frozen rhubarb until just before you’re ready to bake.

Make your own buttermilk: Add 2 teaspoons vinegar or lemon juice per ½ cup 2% or whole milk and let stand for 5 minutes while you mix together your remaining ingredients.