Rhubarb Streusel Cake
This rhubarb streusel cake is buttery and tender, loaded with tangy rhubarb and topped with a cinnamon walnut streusel that bakes up golden and crispy. It’s also known as a rhubarb coffee cake, not because it contains coffee, but because it’s the kind of cake you want to eat with a cup.
About this rhubarb cake
This is a classic coffee cake with a buttery crumb, tangy rhubarb pieces folded through, and a generous layer of cinnamon streusel on top. The cake itself is soft and tender, thanks to yogurt in the batter, which adds moisture and a slight tang that works really well with the rhubarb.
The batter comes together with the standard creaming method (butter and sugar beaten until light, then eggs and dry ingredients folded in). It’s a thick batter, which is what you want. It supports the rhubarb pieces and the heavy streusel topping without sinking.
The streusel is a simple mix of butter, brown sugar, flour, cinnamon, and chopped walnuts, crumbled together by hand. I like making the crumbs in all different sizes so some pieces stay sandy and others crisp up into bigger chunks. The walnuts add a nice crunch, but you can easily swap them for pecans or almonds.
This recipe is baked in a 9 x 13-inch pan, which makes it perfect for feeding lots of people.
Some of the key ingredients and why
- Yogurt: Natural or Greek yogurt keeps the cake incredibly moist and tender. The slight acidity also helps activate the baking soda and creates a finer crumb. You can swap it for sour cream or buttermilk.
- Rhubarb: Fresh rhubarb stalks, chopped small so they soften quickly in the oven and distribute evenly through the cake. Rhubarb is naturally very tart, but when it bakes with the sweet cake batter it becomes soft and flavorful. Frozen rhubarb works too, no need to thaw.
- Brown sugar (in the streusel): While the cake uses granulated sugar, the streusel gets brown sugar for deeper, more caramel-like flavor. It also helps the streusel stay a little chewy in the center of the bigger pieces.
- Cinnamon: A wonderful pairing with rhubarb. It’s in the streusel where it gets toasted in the oven.
Method
- Crumble the butter into the sugar, flour, and cinnamon to make pieces of streusel in all different sizes. Toss in the walnuts.
- Cream the butter and sugar until light and fluffy, then beat in the eggs one at a time.
- Fold in the dry ingredients alternating with the yogurt, starting and ending with the dry.
- Spread thick batter into a pan.
- Scatter the chopped rhubarb over the batter.
- Pile on the streusel crumb and bake.
Tips
Rhubarb Streusel Cake
Ingredients
Streusel Topping
- 60 g all-purpose flour
- 50 g soft brown sugar
- 2 tsp ground cinnamon
- 1/4 tsp salt
- 60 g unsalted butter room temperature
- 50 g walnuts chopped
Cake
- 300 g all-purpose flour
- 2 tsp baking powder
- ¾ tsp salt
- ¼ tsp baking soda
- 170 g unsalted butter room temperature
- 200 g granulated sugar
- 3 large eggs
- 2 tsp vanilla paste or extract
- 240 g natural yogurt room temperature
- 300 g rhubarb chopped
Instructions
- Preheat the oven to 350°F (180°C). Grease or line a 9 x 13-inch baking pan with parchment paper.
- Make the streusel. In a bowl, combine the flour, brown sugar, cinnamon, and salt. Add the room temperature butter and use your fingers to crumble it into the dry ingredients until you have a mix of fine crumbs and larger, cookie-dough-like pieces. Toss in the chopped walnuts and set aside. 60 g all-purpose flour, 50 g soft brown sugar, 2 tsp ground cinnamon, 1/4 tsp salt, 60 g unsalted butter, 50 g walnuts
- Chop the rhubarb into 1/4-inch (1/2 cm) pieces and set aside.
Cake batter
- Whisk together the flour, baking powder, baking soda, and salt in a bowl. Set aside. 300 g all-purpose flour, 2 tsp baking powder, ¾ tsp salt, ¼ tsp baking soda
- In the bowl of a stand mixer fitted with the paddle attachment (or use a handheld electric mixer), beat the butter and sugar on medium speed until light and creamy. Scrape down the sides as needed. 170 g unsalted butter, 200 g granulated sugar
- Beat in the eggs one at a time, followed by the vanilla. The batter may look curdled at this point, that's normal. 3 large eggs, 2 tsp vanilla paste
- Add half the dry ingredients and half the yogurt and fold together gently with a spatula. Add the remaining dry ingredients and yogurt and fold until just combined. Don't over-mix. 240 g natural yogurt
- Spread the batter into the prepared pan using an offset spatula or the back of a spoon.
- Scatter the chopped rhubarb evenly over the batter, then pile the streusel topping on top. 300 g rhubarb
- Bake for 35-40 minutes until the streusel is golden and a skewer inserted into the center comes out with a few moist crumbs (but no wet batter).
- Let the cake cool in the pan for at least 10 minutes before slicing.
Notes
- Yogurt substitution: Natural or Greek yogurt, sour cream, or buttermilk all work.
- Frozen rhubarb: Use straight from frozen, no need to thaw.
- Nut substitutions: Swap walnuts for pecans, almonds, hazelnuts, or macadamia nuts. Or leave them out.
- Storage: Store in an airtight container at room temperature for up to 3 days. Wrap tightly and freeze for up to 3 months.
- Both US customary and metric measurements are provided. Use the toggle to switch between the two.
I don’t have fresh rhubarb, can I use frozen for this recipe? If yes then do I need to thaw the rhubarb first or just mix frozen with the rest of ingredients.
You can use frozen rhubarb and no need to thaw first 🙂