Rhubarb Carrot Cake with Vanilla Mascarpone Frosting
A lightly spiced rhubarb carrot cake recipe with a creamy, dreamy frosting that’s perfect for any spring celebration.
This sophisticated snacking cake features winter carrots and the first rhubarb of the year in a marvellous merging of two seasons.
I’m so excited to bring you this recipe after many rounds of testing. Part spiced carrot cake and part rhubarb coffee cake, this is the springtime dessert mashup you need as winter melts away.
It’s scented with cinnamon and nutmeg and generously frosted with a decadent whipped mascarpone. But it’s those jammy nuggets of baked rhubarb inside that really make this carrot cake unique.
Rhubarb Carrot Cake Inception
For years I’ve added chopped fresh rhubarb to my Oatmeal Carrot Muffins and always loved the combination of carrots and rhubarb.
I decided to test the combo in cake form, inspired by Elizabeth Baird’s famous Lunar Rhubarb Cake. Last spring (and the spring before that, to be honest) I worked on the recipe you see here.
I nailed it by late June, but then was so sick of rhubarb, I just wanted to move onto wild blueberries. Such is the life of a recipe developer.
Now? The rhubarb enthusiasm is back in full force. I was practically giddy to find the florescent pink stalks in my local gourmet foods store.
Sure these are greenhouse-grown, forced vegetables, but they will do while my own rhubarb is still a cluster of bright pink buds in the semi-frozen earth.
Rhubarb + Cake seems to be a springtime obsession with me. Who could forget this Victoria Sponge Cake with Strawberry Rhubarb Jam? Or my Lemon Ricotta Pound Cake with Roasted Rhubarb Compote?
This 2021 version is my best ever. You’ll just have to try it for yourself and see what I mean.
Baker’s Notes for Rhubarb Carrot Cake:
- I use a 9-inch springform pan, as this cake is quite tall. See notes below for other variations.
- I’ve tested the cake with the addition of walnuts in the batter – and it’s delicious! I left them out of the recipe because I ultimately wanted the rhubarb to shine. It’s your call.
- I decorated it with simple raw ribbons of rhubarb and carrots, you could also have fun with edible flowers or chopped nuts.
- This cake keeps for 2 days, loosely covered and stored in the refrigerator.
- Use a sharp chef’s knife to cut the cake.
- Read a refresher on rhubarb including buying, storing and freezing.
Rhubarb Carrot Cake variations
Snack Cake: This rhubarb carrot cake makes a terrific ‘counter cake’ in it’s simplest, unfrosted form. The cinnamon sugar topping caramelizes in the oven, much like a coffee cake. Served warm, with a cup of coffee, this snack cake is hard to beat.
Brunch Cake: Bake it in a 9×13 pan and leave it unfrosted. Serve it warm from the oven with a side bowl of creamy yogourt for the ultimate brunch dessert.
Layer Cake: Another option I tested was to bake two 8-inch round cakes with the batter and layer them up with the whipped mascarpone frosting. This version is slightly more elegant, especially when decorated with spring flowers.
Whether you’re celebrating Easter, the arrival of spring, or getting that coveted vaccine, this comforting rhubarb carrot cake is a super fun weekend baking project.
Rhubarb Carrot Cake
Ingredients
- 1/2 cup unsalted butter room temperature
- 1 cup white sugar
- 1/2 cup brown sugar divided
- 1 large egg room temperature
- 1 teaspoon pure vanilla extract
- 2 cups cake flour
- 1 teaspoon baking soda
- 1/2 teaspoon fine sea salt
- 1/4 teaspoon freshly grated nutmeg
- 1 cup grated raw carrots loosely packed
- 1 1/4 cups chopped fresh rhubarb 1/2 -inch pieces
- 1 cup buttermilk room temperature
- 1 1/2 teaspoons ground cinnamon
Instructions
- Butter a 9-inch round springform pan and line the bottom with parchment paper. Preheat the oven to 350°F.
- In the bowl of a stand mixer fitted with the paddle attachment, combine butter, white sugar and 1/4 cup brown sugar. Beat at medium speed until light and creamy. Scrape down the sides of the bowl once or twice during the mixing.
- Crack in the egg and add the vanilla. Beat again until very well combined. Scrape down the sides of the mixing bowl.
- Sift the flour and baking soda into a separate bowl. Whisk in the salt and nutmeg. Measure out 2 tablespoons of this flour mixture and toss with the rhubarb and carrots in another bowl.
- With the mixer on Low, add the dry ingredients to the creamed butter in three parts, alternating with the buttermilk. Flour, mix lightly. Buttermilk, mix lightly. Flour, mix. Buttermilk…finishing with the flour.
- Add the rhubarb & carrots to the cake batter and gently stir to combine. Scrape the batter into the prepared cake pan and smooth the top.
- Mix together the remaining 1/4 cup of brown sugar with the cinnamon. Sprinkle over the cake batter. Run a butter knife through the cake, making a few figure eights to swirl the cinnamon into the batter.
- Place the cake on a middle rack in the center of the oven and bake until a toothpick inserted in the middle comes out clean. About 1 hour or 1 hour and 10 minutes. It will get quite dark on the top.
- Cool the cake for 10 minutes on a wire rack, then loosen around the edges and remove the ring. When cool, frost generously with Whipped Mascarpone Frosting (recipe below), then slice and serve.
Notes
Nutrition
Our family never have been big fans of overly sweet frosting and so we found this vanilla-scented, lightly sweetened whipped mascarpone to be the perfect topping to our rhubarb carrot cake.
My friend Tessa says that mascarpone helps to stabilize whipped cream. We both love the richness that it brings to a cake topping or filling.
Whipped Mascarpone Frosting
Ingredients
- 1 cup mascarpone room temperature
- 1 cup heavy cream 35%
- 1/4 cup granulated sugar
- 1/2 vanilla bean, scraped or 1 tsp pure vanilla
Instructions
- In the bowl of a stand mixer fitted with the whisk, combine all of the ingredients.
- Whip on high until the cream holds soft peak. Do not walk away; the cream whips very fast! Do not over mix as the frosting may become grainy.
- Use immediately for frosting Rhubarb Carrot Cake. Leftover frosting may be refrigerated for up to 2 days.
This is all I want in a spring cake. The hint of spices leftover from winter and yet the brightness of the rhubarb and the carrots! I love the idea of mascarpone in the frosting, we’re not big icing fans here either.
I just used our last rhubarb from the freezer this week and will wait for our garden to come up fresh to bake this up!
Hey Breanne, it will be worth the wait. Here’s hoping you don’t have to wait too much longer for spring to arrive. xox
Love the recipe. Thank you for sharing!
A lovely cake, and just so versatile! Thanks Aimee!
wonderful, love this combination of carrot and rhubarb! Sweet and not so sweet in a very nice way, thank you!
Wow, this cake looks amazing. I look forward to making this soon.
Made this cake with fresh carrots and rhubarb from the garden and a fresh egg from the chickens, in an 8×11.5” pan and it turned out AWESOME! The whole family loved it.
The first time I made this I used rhubarb. It was great!
This time I couldn’t find rhubarb, so I used frozen cranberries. It came out perfect again!
I will keep this recipe handy….
As always you have brilliant recipes! I was wondering do you have a gluten free version of this recipe?
I have some very sweet carrots I don’t like to munch on. My rhubarb cake recipe is very good and I was thinking of combining the carrots with the rhubarb. Your receipe will make that easier. I have not yet make your cake version, but love the format of your receipe. I will make a comment when I bake and try the cake.
Liliana
Just tried it. Amazing flavours. My new favourite cake.