If you are anything like me, you’ve got an out-of-control rhubarb plant somewhere in the backyard that seems to grow overnight as soon as spring/summer hits. I can’t keep up with the thing! In an attempt to use up a portion of that deliciously sour and abundant vegetable, I decided to bake this amazing gluten-free and dairy-free raspberry rhubarb cake. Probably my new favorite way to consume rhubarb.
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Gluten-Free & Dairy-Free Raspberry Rhubarb Cake
Pillowy soft layers of light almond cake that are baked to gorgeous fluffy perfection. A sweet raspberry rhubarb filling with a subtle sour hint. All gloriously wrapped up in the most delicious whipped white chocolate buttercream frosting you will ever try! This gluten-free and dairy-free raspberry rhubarb cake will knock your socks off and have you looking forward to each and every rhubarb harvest all summer long.
What Makes Up A Raspberry Rhubarb Cake
With a sweet and fresh flavor profile, this raspberry rhubarb cake is made up of 4 different components:
Almond cake layers – super soft and fluffy almond cake layers made with a tiny bit of pure almond extract.
Raspberry rhubarb filling – this fresh raspberry rhubarb filling is so incredibly yummy. It’s the perfect filling for this summer cake with notes of sweet raspberry and a hint of sour rhubarb.
White chocolate frosting – the fluffiest whipped white chocolate buttercream made with melted dairy-free white chocolate. It’s pure decadence and you’ll want to eat it by the spoonful.
White chocolate drip – while not necessary, this dairy-free white chocolate drip is a gorgeous design element that creates an incredibly elegant appearance to the final cake.
Raspberry Rhubarb Cake Ingredients
As always this recipe is gluten-free and dairy-free. That said, I do test each recipe with “regular” ingredients and make notes of alternatives or swaps so that everyone can enjoy it.
Here are a few key ingredients for this cake but make sure you scroll all the way to the bottom recipe card for the complete ingredient list.
Gluten-Free Flour: Check to see if your blend contains xanthan gum. This can also be swapped for regular cake flour if you are not gluten-free. Note that gluten-free flour blends can vary in weight so I recommend measuring by the cup. I made this cake with Cloud 9 all-purpose baking mix. If you are not gluten-free, swap the flour with regular cake flour and omit the xanthan gum.
Dairy-Free Butter: I enjoy baking with BECEL plant-based bricks but any dairy-free butter substitute will work. You can also use regular butter if you are not dairy-free.
Dairy-Free Milk: I love to bake with unsweetened almond milk but this recipe will work with any type of dairy-free or dairy milk.
Oil: Use canola or vegetable oil for best results.
Raspberries & Rhubarb: Fresh is best, that’s at least my motto when it comes to fruit, but frozen will totally work in a pinch or on a budget.
Almond Extract: This recipe calls for pure almond extract. While not necessary, it does add a delicious flavor that I think pairs beautifully with the other components. Feel free to swap it with vanilla extract though. I love baking with Watkins pure almond extract.
Dairy-Free White Chocolate: I used Pascha dairy-free white chocolate in both the buttercream and the drip. Swap with regular white chocolate if you are not dairy-free.
Liquid Whitener Food Color: This nifty little decor ingredient helps whiten and brighten the frosting and chocolate drip. It’s not necessary but super helpful if you desire a pure white color. I use Chefmaster liquid whitener as it’s vegan and gluten-free. Alternatively, you can add a toothpick tip of purple gel color to the frosting and chocolate drip as the purple cancels out the yellow. But be careful as a little goes a long way.
The Best Dairy-Free Raspberry Rhubarb Filling
What would a raspberry rhubarb cake be without raspberry rhubarb filling? It’s the perfect balance between sweet and sour and packs a flavor punch with each bite. It’s the star of this cake show and I wouldn’t bat an eye if you doubled the recipe and kept the extra filling for a tasty ice cream topper or even a delicious spread for toast or pancakes.
The trick to making the best dairy-free raspberry rhubarb filling is to go low and slow. Cooking over lower heat for a longer time allows the rhubarb to fully break down so you’re not left with any stringy or crunchy bits.
How To Make Raspberry Rhubarb Filling
Start by ensuring the rhubarb is finely chopped. Feel free to remove any stringy bits too if you notice them while chopping. Combine all of the filling ingredients in a medium heavy-bottomed pot and begin to cook over medium heat. Remember, low and slow is the goal here.
While stirring occasionally, allow this mixture to come to a boil. Depending on whether you used fresh or frozen fruit, this should take approximately 10 minutes. Once the raspberry rhubarb filling comes to a boil, reduce the heat to medium-low and allow it to very gently simmer for an additional 5 minutes. Continue to stir as it cooks.
Seeds Or No Seeds: It’s Up To You
After 5 minutes on medium-low heat, the filling should be smooth and thick enough to coat the back of a spoon. Now’s the time to remove it from the heat and pour it into a shallow dish to cool. Side note: if you’re not a fan of raspberry seeds, you can strain the filling with a fine-mesh sieve. I personally like the texture of raspberry seeds but hey, to each their own!
Place a piece of plastic wrap directly on the surface of the raspberry rhubarb filling and allow it to fully cool to room temperature before using it in the cake. As the filling cools, it will thicken even more. If you’d like to speed up the cooling process, go on ahead and put it in the fridge to chill faster.
Raspberry Rhubarb Cake: Step By Step Instructions
Step 1: Mix the flour, baking powder, salt, and xanthan gum (if using) together and set aside.
Step 2: Cream together the butter, sugar, and oil until light and fluffy, and then add in the eggs and almond extract.
Step 3: Combine the dry ingredients with the wet ingredients and begin to mix.
Step 4: Slowly pour in the almond milk and mix until just combined.
Step 6: Divide the cake batter into three 8-inch cake pans that have been prepared with baking spray and parchment paper and bake for approximately 20-25 minutes. Cool cakes on a cooling rack.
Step 7: Prepare the raspberry rhubarb filling and allow it to fully cool before using it in the cake.
Step 8: Cream the butter in a mixer on high speed for 10 minutes until light and fluffy. Add in the icing sugar and salt and mix until combined. Add in the melted white chocolate and white gel color (if using) and mix until combined.
Step 9: In a microwave-safe bowl, prepare the white chocolate drip and pour on a well-chilled cake.
Cake Assembly Tips
Stacking a cake with a soft filling such as this raspberry rhubarb cake can feel a bit daunting. But, as they say, slow and steady wins the race. Let’s set you up for cake success with a few tips and tricks.
Here are a few assembly tips:
- Fully cooled cake layers and filling: even if a tiny bit warm, layers and/or filling will slip when warm. Ensure that each cake layer and the filling are fully cooled if not even a bit chilled. I will even work with semi-frozen cake layers if I had to bake them a few days before stacking.
- Leveled cake layers: flat and level cake layers will sit far easier than crooked ones. I use this super easy cake tool to ensure each cake layer is perfectly level.
- Create a frosting border: this piped frosting border between each cake layer acts as a dam to keep that delicious raspberry rhubarb filling in.
- Keep the cake chilled: if at any point you begin to feel the cake slip or the frosting is too soft to work with, pop the cake and the frosting back into the fridge to chill.
How To Decorate A Raspberry Rhubarb Cake
“As you desire” is often how I refer to cake decoration. It’s not that I don’t want you to make the exact same cake as I did, it’s simply that I don’t want you to feel like you *have* to make the exact same cake. We all have an inner cake artist and I always want to encourage you to let it shine. That said, I break down this gluten-free and dairy-free raspberry rhubarb cake decor for you real quick.
Step 1: Crumb-coat the entire cake and allow it to chill for 20 minutes. See the above section for stacking tips and tricks.
Step 2: Put a final “beauty” coat of frosting on the cake and smooth the sides with a cake smoother. With an offset spatula, clean the top edge off to produce clean sharp edges. Chill the cake while you prepare the drip.
Step 3: Using a piping bag with the tip cut off or even with a spoon, pour the white chocolate drip over the edges of a well-chilled cake. I always test my drip on the edge of my kitchen sink first to check the consistency. You want it thin enough to drip down but not too far down. Try one drip on the cake and see how it falls. Continue if you like it and stop if you don’t. If you need a thinner drip, add a tiny bit more milk. If you need a thicker drip, add a bit more chocolate. Test again until you are happy with it. Chill the cake once the drip is done.
Step 4: Gently pat dry some extra raspberries and rhubarb and place them around the top edge of the well-chilled cake much like you are creating a wreath.
Step 5: Chill the cake until ready to serve.
Storing and Freezing Instructions
This cake can be kept in an airtight container in the fridge for up to 7 days. It can also be stored in the freezer for up to 6 months.
If you want to bake these layers a few days in advance, you most certainly can. I recommend allowing the cake layers to cool, wrapping them in plastic wrap, and freezing them until you a ready to stack and decorate the cake. Simply remove the layers from the freezer approximately 1 hour before for them to thaw slightly.
The Yummiest Gluten-Free Raspberry Rhubarb Cake
A slice of summer delight, this amazing gluten-free and dairy-free raspberry rhubarb cake is a delicious combo of sweet, tart, and smooth in every single bite. Fluffy almond cake layers with raspberry rhubarb filling and covered in a magnificent whipped white chocolate buttercream frosting. This summer raspberry rhubarb cake is fresh, fruity, and a definite must-bake!
Make sure you tag me on social media @cakedbykatie and leave me a rating and review below if you make it. Can’t wait to see it!
Fruity Baking Recipes
Here are a few other fresh fruity recipes that practically scream summer:
- Gluten-Free Lemon Blueberry Layer Cake
- Gluten-Free Orange Creamsicle Cake
- Gluten-Free Coconut Cake
- Pina Colada Cake
- Sangria Cupcakes
- Lemon Raspberry Layer Cake
- Raspberry Blondies
- Cherry Oatmeal Cookies