Rhubarb Buttery Cake (Rabarberkaka)
Updated: Jun 3, 2019
Rhubarb season is in full bloom. In our house one cake which we can’t get enough of at this time of the year is Rabarberkaka - traditional Swedish rhubarb cake. It’s simple, quick and full of flavour.
Our version is a typical quick bake (20min prep) with explosion of ground and citrusy notes brought by cardamom, caramel notes thanks to demerara and pearl sugars and sweet&sour notes brought by rhubarb. All is complemented by butter which is added just at the end as a topping (rather than into the cake batter) creating crunchy and buttery skin on the outside.
Most of our quick bakes are puffy. This cake does not rise much but still manages to deliver soft and fluffy texture. We are intentionally not adding baking soda or baking powder - the cake relies solely on simple ingredients and mix of flavours.
Rhubarb is tossed in cardamom and sugar. Light cake batter is created by simply beating eggs with sugar for 10 minutes (key to success in this bake), small amount of flour is gently folded in as a last step. Spiced rhubarb is placed on top of the cake. To get the crunchy topping, thin slices of cold butter are spread on top of the rhubarb. All is then sprinkled with demerara and pearl sugars. Why demerara sugar? This large grained, somewhat crunchy, raw sugar has a natural caramel-like flavour; this lends warm, caramel notes to whatever you add this type of sugar to. Then, pearl sugar adds to the caramel notes and crunchy texture (part is melting into the cake, part is staying intact after baking).
This is one of the cakes which disappears warm and in one sitting! Does not look like a WoW cake but more than makes up for that thanks to the explosion of sour-sweet, buttery and crunchy caramel flavours.
Serve warm, sprinkled with pearl sugar and a generous scoop of vanilla ice-cream!
Rhubarb Buttery Cake (Rabarberkaka) Recipe
Yield: 12 servings
Time: 20 minutes prep + 40-45 minutes baking
Tin: 21cm round with removable base (spring form) or 26cm (bake from 1.5 portion)
- 350g rhubarb
- 1/2 teaspoon freshly ground cardamom (optional)
- 1 Tablespoon (15g) caster sugar (skip if not using cardamom)
- 2 large eggs, room temperature
- 1/2 cup (100g) caster sugar
- 1/8 teaspoon salt
- 2/3 cup* (100g) all-purpose flour
- 50g unsalted butter, straight from the fridge or freezer
- 20g demerara brown sugar
- 30g pearl sugar + 15g to decorate
1. Preheat oven to 180C. Line baking tin with parchment paper, grease sides with butter.
2. Prepare rhubarb: Cut rhubarb into 0.3cm thin slices, toss in cardamom and sugar mixture. If you are not using cardamom - skip sugar (you will be placing plain rhubarb on the cake).
3. Prepare cake batter: Beat 2 large eggs on low speed for 2 minutes, after that time start adding sugar - 1 Tablespoon at a time increasing speed to medium and making sure sugar is well incorporated in-between additions, 5 minutes into mixing increase speed to high. It will take you 10 minutes to fully incorporate sugar and beat eggs until creamy using stand mixer (or 12-15 minutes using hand held mixer). As a last step add salt and continue mixing for another 1 minute. Sift flour into the egg mixture and using spatula gently fold in - only until combined, making sure no flour pockets remain. Once ready pour batter into the tin, spread rhubarb on top of the cake. Now apply cake topping: take out cold butter, cut thinly (or grate) and spread across the cake. Then sprinkle the top with demerara sugar and pearl sugar.
4. Bake at 180C for 40-45 minutes. Check with the skewer if fully baked through. Once baked, let it cool for 10 minutes, then run thin knife around the parameter and release the cake. Decorate the cake with crunchy pearl sugar. Serve warm with generous scoop of vanilla ice-cream.
1. Cardamom is optional here but highly recommended. It will give additional, citrusy-woody dimension to sweet-sour rhubarb.
2. Beat eggs for full 10 minutes using stand mixer (12-15 minutes using hand held mixer). This is a key for a good bake here. By doing this you will guarantee light and airy texture.
3. Butter - use cold, straight from the fridge or freezer (even better). You can cut it or grate it on the largest grater scale.
4. If you can’t get demerara and pearl sugars - sprinkle the top with 1/5 cup (40g) light brown or caster sugar mixed with 1/2 teaspoon cinnamon.