It’s rhubarb season, time for rhubarb cake. I bought fresh rhubarb at the local market…so here we go! What works well with rhubarb…? Brown sugar!
I used dark brown sugar in this recipe because the higher percentage of molasses adds more flavor to this cake. Dark brown sugar has a malty, slightly tart flavor and creates a good contrast to the acidity of the rhubarb. In combination with buttermilk, the sugar gives the cake a nice moist crumb and a well balanced sweetness.
Tools & Equipment
- 22,9cm / 9-inch round cake pan
- Cutting board
- Parchment paper
- Sharp knife
- Silicone spatula
- Stand mixer fitted with paddle attachment
- Wire rack
Recipe Tips
Cake Pan: I used a round cake pan for this cake. However, I would suggest using a springform pan, because it makes it much easier to remove the cake from the pan. The cake is very moist, so it is a bit difficult to release it from the round cake pan.
Brown Sugar: the main difference between light and dark brown sugar comes down to the taste. Light brown sugar contains about 3.5% molasses, while dark brown sugar contains about 6.5% molasses, resulting in a more intense flavor with notes of caramel and toffee. There are also small differences in texture, but this is not a problem and you can easily substitute them. If you can’t find any brown sugar, you can make it yourself: combine 200g of granulated sugar and 13g of molasses in a food processor and let it run until it has a uniform color. You can buy molasses in health food stores/drugstores.
Rhubarb on Top of the Cake: if you want to have pieces of rhubarb on top of your finished cake, you should bake the cake for about 20 minutes, then top with rhubarb, sprinkle with sugar (Step 9 of Recipe instructions) and bake for another 20-25 minutes.
Directions – How to Make a Brown Sugar Rhubarb Cake
Preheat the oven to 180°C / 350°F. Grease a round 22, 9cm/9-inch cake pan or a springform pan and line with parchment paper. Set aside. Prepare the rhubarb: Wash thoroughly and peel the rhubarb with a sharp knife.



Weigh all ingredients and slice or dice the rhubarb.

Beat butter, brown sugar and zest in the bowl of a stand mixer at medium to high speed until fluffy, for about 3 to 4 minutes. Scrape down the sides and bottom of the bowl.


Add the eggs, one at a time and beat for about 1 minute on medium speed after each addition. Stir in the vanilla.



Combine the flour, baking powder and salt in a medium bowl. Reduce the speed of the mixer to low and gradually add the flour mixture alternating with buttermilk, starting and ending with flour mixture and beat until just combined after each addition. Scrape down the sides and bottom of the bowl.



Fold in the diced rhubarb. Transfer the batter into your prepared round or springform pan. Top with the diced or sliced rhubarb and sprinkle with granulated sugar.



Bake for 40 to 50 minutes, until a toothpick comes out clean. Let the cake cool in the pan for 30 minutes. Then remove it from the pan and place it on a wire rack to cool completely.

Storage: you can store the cake well-wrapped or under a cake dome at room temperature for up to 3 days.


My Summary for Brown Sugar Rhubarb Cake
Difficulty: simple.
Taste: the dark brown sugar makes the cake taste like toffee or caramel and creates a nice sweet-sour balance in combination with the rhubarb and the buttermilk.
Texture: this cake has a moist crumb with a crunchy top.
PROS: a simple recipe that doesn’t require much equipment.
CONS: this rhubarb cake tastes “good” on the day it’ s baked. But the flavor is so much better the next day, because everything has set. I suggest making this cake one day in advance, therefore you need to plan ahead.
