If you’re looking for a delightfully tangy and sweet treat that feels like a warm hug from an old friend, this Rhubarb Streusel Cake Recipe is just what you need. Bursting with fresh rhubarb’s tart punch and topped with a buttery, crunchy streusel, this cake strikes the perfect balance between moist crumb and crispy topping. It’s perfect for cozy get-togethers, afternoon tea, or just savoring on a quiet weekend afternoon. Trust me, once you try this recipe, it will quickly become a cherished favorite in your baking repertoire.

Ingredients You’ll Need

The image shows an overhead view of various baking ingredients neatly arranged on a white marbled surface. There are eleven white bowls and small metal cups, each holding different items: a large bowl of flour, a medium bowl of sliced red and green rhubarb pieces, a bowl with melted yellow butter, another bowl with brown sugar, and a bowl of white sugar. There is a small bowl with two blocks of butter, a single white egg, and a clear glass measuring cup filled with white milk. Three small metal bowls contain white baking powder, baking soda, and salt, while another metal cup holds a dark brown liquid, likely vanilla extract. A blue and white checkered cloth is partially visible in the bottom left corner. The items are spaced evenly, showing a clean, organized setup for baking. Photo taken with an iphone --ar 4:5 --v 7

Gathering simple but essential ingredients is key to making this rhubarb streusel cake sing. Each one plays a special part, whether it’s the tangy buttermilk tenderizing the crumb or the brown sugar creating that rich, caramelized streusel topping.

Unsalted butter (2 tablespoons, softened): Gives the batter a luscious richness and helps the cake stay moist.
Granulated sugar (1 cup): Sweetens the cake evenly without overpowering the rhubarb’s tartness.
Large egg (1): Binds all the ingredients together while adding a natural richness.
Pure vanilla extract (1 teaspoon): Enhances the flavors and adds a subtle warmth.
All-purpose flour (2 cups): The foundation for a tender, yet structured cake crumb.
Baking powder (1 teaspoon): Ensures the cake rises just right for a light texture.
Baking soda (1/2 teaspoon): Works with the buttermilk to give a soft and airy crumb.
Fine sea salt (1/2 teaspoon): Balances the sweetness and heightens all the flavors.
Buttermilk (1 cup): Adds moisture and a slight tang that complements the rhubarb perfectly.
Chopped fresh or frozen rhubarb (3 cups): The star ingredient that brings bright, tart notes and beautiful pink streaks in every bite.
All-purpose flour (1/2 cup for streusel): Helps create the crumbly, buttery topping you’ll adore.
Lightly packed light brown sugar (1/2 cup): Infuses the streusel with deep caramel flavor.
Unsalted butter (4 tablespoons, melted for streusel): Binds the streusel ingredients and crisps up nicely in the oven.

How to Make Rhubarb Streusel Cake Recipe

Step 1: Prep Your Pan and Preheat

Kick things off by preheating your oven to 350°F so it’s nice and hot when your batter is ready. Spray a 9×9-inch cake pan generously with nonstick spray to ensure an easy release — this simple prep makes all the difference when your cake comes out golden and perfect.

Step 2: Cream Butter, Sugar, Egg, and Vanilla

In a large bowl, use an electric mixer to beat the softened butter, granulated sugar, egg, and vanilla extract on medium speed. You want to whip this mixture until it’s light in color and perfectly blended, which sets the base for your tender cake crumb.

Step 3: Combine Dry Ingredients Separately

Whisk together your all-purpose flour, baking powder, baking soda, and salt in a separate bowl. This ensures even distribution of leavening agents throughout the batter, so your cake rises uniformly with a fine texture.

Step 4: Alternate Adding Dry Ingredients and Buttermilk

With your mixer on low, add half of the flour mixture to the buttery sugar mix, stirring just until combined. Then pour in all the buttermilk, mixing carefully to keep things light and tender. Finish by folding in the rest of the flour mixture, making sure to scrape down the sides for an even batter.

Step 5: Fold in the Rhubarb

Gently fold the chopped rhubarb into the batter, distributing those little bursts of tart yum evenly throughout. If you’re using frozen rhubarb, fold it in without thawing to avoid watering down the cake.

Step 6: Spread Batter and Prepare Streusel

Pour your batter into the prepared cake pan, smoothing it out evenly with a spatula. Next, mix together the streusel ingredients — flour, light brown sugar, and melted butter — until clumps form. Sprinkle this crumbly topping generously over the batter for that signature crunch.

Step 7: Bake Until Golden and Set

Bake your cake for 60 to 70 minutes, or until a toothpick inserted into the center comes out clean. This is where patience pays off as the cake develops its tender crumb and those streusel topping morsels turn golden brown and irresistible.

Step 8: Cool and Enjoy

Let the Rhubarb Streusel Cake Recipe cool completely in the pan before slicing. This helps the cake set and makes serving less messy, giving you perfect squares of tart, sweet delight every time.

How to Serve Rhubarb Streusel Cake Recipe

The image shows a square metal baking pan lined with white parchment paper, filled with an unbaked batter mixed with chopped red and green fruit pieces evenly spread throughout. The batter is smooth and pale creamy yellow, with the fruit pieces creating irregular red and green spots in it. The pan sits on a white marbled surface with two red rhubarb stalks on the top left and a blue and white checkered cloth partially visible at the bottom left corner. photo taken with an iphone --ar 4:5 --v 7

Garnishes

For an extra touch, dust the cake lightly with powdered sugar just before serving or add a dollop of freshly whipped cream. The creamy sweetness is a lovely contrast to the rhubarb’s tang and the crisp streusel.

Side Dishes

This cake pairs beautifully with a scoop of vanilla ice cream or a simple cup of black coffee or tea. The warmth and bitterness of your drink will highlight the cake’s rich flavor, making each bite even more satisfying.

Creative Ways to Present

Try slicing the cake into wedges for a rustic, café-style presentation or cut it into bite-sized squares for a delightful dessert buffet. You can also serve it alongside a fresh berry compote to add another layer of fruity brightness to your Rhubarb Streusel Cake Recipe.

Make Ahead and Storage

Storing Leftovers

Keep leftover cake covered in an airtight container at room temperature for up to 2 days, or refrigerate if you want to keep it fresh a little longer. The flavors actually deepen after a day, making it even tastier.

Freezing

You can freeze this cake by wrapping it tightly in plastic wrap and then aluminum foil. It will keep well in the freezer for up to 2 months. When you’re ready to enjoy it, thaw overnight in the fridge for best results.

Reheating

Warm individual slices in the microwave for about 15 seconds or pop them in a warm oven for a few minutes. This refreshes the cake’s softness and will bring back that streusel crunch like it was freshly baked.

FAQs

Can I use frozen rhubarb in this Rhubarb Streusel Cake Recipe?

Absolutely! Just be sure not to thaw the frozen rhubarb before folding it into the batter to avoid extra liquid, which can change the cake’s texture.

What if I don’t have buttermilk? Can I substitute it?

Yes, you can make a quick substitute by adding 1 tablespoon of lemon juice or white vinegar to a cup of milk. Let it sit for 5 minutes, and it acts just like buttermilk in this recipe.

How do I know when the rhubarb streusel cake is fully baked?

Insert a toothpick or cake tester into the center of the cake; if it comes out clean or with a few moist crumbs, your cake is done. The streusel should also be golden and crisp on top.

Can I make this cake dairy-free?

With a few ingredient swaps like using a non-dairy butter and plant-based buttermilk (such as almond milk mixed with vinegar), you can enjoy a dairy-free version that’s just as delicious.

What’s the best way to get a crunchy streusel topping?

Using cold butter and mixing the streusel ingredients until clumps form helps create a wonderfully crumbly and crisp topping after baking. Don’t skip melting the butter if the recipe calls for it, as it binds everything perfectly.

Final Thoughts

This Rhubarb Streusel Cake Recipe is a shining example of how simple ingredients come together to create something truly memorable. Its tender crumb, vibrant rhubarb, and crunchy topping make it the kind of dessert you’ll want to bake again and again. Whether you’re a baking novice or a seasoned pro, give it a try and watch it become an instant classic on your dessert table.