Rhubarb Streusel Cake with Warm Vanilla Sauce Recipe
If you’re searching for a dessert that perfectly balances tangy fruit, buttery crumb, and luscious sauce, you’re about to fall in love with this Rhubarb Streusel Cake with Warm Vanilla Sauce Recipe. Each forkful delivers a cozy mix of tender cake studded with tart, juicy rhubarb, a golden-brown cinnamon streusel, and a dreamy vanilla sauce that’s decadently smooth. Whether you’re a longtime rhubarb fan or trying it for the first time, this recipe is a showstopper at any gathering and brings a nostalgic, old-fashioned charm to your table.

Ingredients You’ll Need
Don’t let the list fool you—these ingredients are pantry basics with a few seasonal standouts. Every component, from the tangy rhubarb to the silky cream, plays a key role in making this Rhubarb Streusel Cake with Warm Vanilla Sauce Recipe irresistibly memorable.
- All-purpose flour: The backbone for both cake and streusel, it creates a light, tender crumb and a perfect crispy topping.
- Baking soda: Gives lift and keeps the cake fluffy as it bakes.
- Salt: Just a pinch sharpens all the flavors, so don’t skip it!
- Granulated sugar: Adds sweetness to the cake and the sauce, balancing the tartness of the rhubarb.
- Large egg: Binds everything together for a cohesive, rich texture.
- Sour cream: The secret to moistness—this keeps your cake tender and adds a gentle tang.
- Vegetable oil: Makes the crumb extra soft and keeps the cake fresh longer.
- Vanilla extract: Adds warmth and aroma to both cake and sauce—don’t hold back on quality!
- Fresh rhubarb: The star ingredient, chopped for pops of tart flavor and gorgeous color.
- Brown sugar: For the streusel, it brings deep molasses notes and lovely caramelization.
- Cinnamon: A pinch of spice in the streusel for cozy warmth.
- Unsalted butter: Used cold for the streusel’s crunch and melted for the silky sauce.
- Heavy cream: Essential for making the vanilla sauce decadently rich and smooth.
- Milk: Lightens the sauce while keeping it creamy.
- All-purpose flour (for sauce): Helps thicken the sauce to the perfect pouring consistency.
How to Make Rhubarb Streusel Cake with Warm Vanilla Sauce Recipe
Step 1: Prep Your Pan and Oven
Start by preheating your oven to 350°F (175°C) and greasing a 9×13-inch baking dish. This ensures your cake will release easily and bake evenly. A well-prepped pan is the foundation for cake success!
Step 2: Mix the Dry Ingredients
In a large bowl, whisk together the all-purpose flour, baking soda, salt, and granulated sugar. This quick mix disperses the leavening and salt, so your cake rises beautifully and every bite tastes just right.
Step 3: Combine the Wet Ingredients
In another bowl, whisk the egg, sour cream, vegetable oil, and vanilla extract until smooth. The sour cream adds unbeatable moistness, while the vanilla brings out the best in the rhubarb. Make sure this mixture is well combined for even results.
Step 4: Bring It All Together
Pour the wet mixture into the bowl of dry ingredients and stir gently until just combined—don’t overmix! Fold in the chopped fresh rhubarb for those juicy, tart pockets that make this cake sing. Spread the batter into your prepared baking dish and smooth the top.
Step 5: Make the Streusel Topping
In a small bowl, combine the brown sugar, flour, and cinnamon. Using a pastry cutter or fork, cut in the cold, cubed butter until the mixture looks like coarse, buttery crumbs. Sprinkle the streusel evenly over the cake batter for a sweet, crunchy crown.
Step 6: Bake
Slide your cake into the oven and bake for 40–45 minutes. Check with a toothpick—the cake is done when it comes out clean or with just a few moist crumbs. The aroma of cinnamon and rhubarb filling your kitchen is a treat in itself!
Step 7: Prepare the Warm Vanilla Sauce
While the cake bakes, start the sauce. In a small saucepan over medium heat, whisk together granulated sugar, flour, and milk. Add heavy cream and butter, and cook, stirring constantly, until the mixture starts to simmer and thickens slightly, about 5–7 minutes. Remove from heat and stir in vanilla extract for that signature finishing touch.
Step 8: Serve and Savor
Cut the warm cake into slices and serve with a generous pour of the luscious vanilla sauce. Whether you enjoy it warm from the oven or at room temperature, every bite is pure comfort!
How to Serve Rhubarb Streusel Cake with Warm Vanilla Sauce Recipe

Garnishes
A sprinkle of powdered sugar on top or a few extra pieces of fresh rhubarb make for a stunning presentation. Try a dollop of lightly whipped cream or a handful of sliced almonds for extra flair and crunch. These little touches elevate the visual appeal and add just the right finishing flourish.
Side Dishes
This cake shines on its own, but it’s also lovely paired with a scoop of vanilla ice cream or a side of fresh berries. For a special brunch, serve it with hot coffee, tea, or even a sparkling lemonade. The sweetness and tartness of the cake complement creamy, fruity, or citrusy sides beautifully.
Creative Ways to Present
For a party, slice the Rhubarb Streusel Cake with Warm Vanilla Sauce Recipe into elegant squares and serve on a tiered dessert stand. If you’re feeling playful, serve individual portions in mason jars, layering cake cubes and sauce for a parfait effect. Or, try baking in muffin tins for adorable single-serve treats—just adjust baking time accordingly!
Make Ahead and Storage
Storing Leftovers
Keep any leftover cake covered at room temperature for up to two days, or refrigerate for up to five days. The vanilla sauce should be stored in an airtight container in the fridge as well. A quick reheat will bring back all that just-baked magic!
Freezing
The Rhubarb Streusel Cake with Warm Vanilla Sauce Recipe freezes surprisingly well. Wrap slices or the whole cake tightly in plastic wrap and foil, then freeze for up to two months. The vanilla sauce can also be frozen—just place it in a freezer-safe container and thaw overnight before reheating gently.
Reheating
To reheat the cake, simply warm slices in the microwave for 15–20 seconds or place in a low oven (300°F) for a few minutes. For the vanilla sauce, heat gently in a saucepan or the microwave, stirring often to keep it silky smooth. Pour the warm sauce over your cake just before serving for the ultimate treat!
FAQs
Can I use frozen rhubarb instead of fresh?
Absolutely! Frozen rhubarb works wonderfully in this recipe. Just be sure to thaw it completely and drain any excess liquid to prevent the cake from becoming soggy.
What if I don’t have sour cream?
If you’re out of sour cream, plain Greek yogurt is a fantastic substitute. It delivers the same tang and moist texture, so your cake will turn out just as delicious.
Can I make the vanilla sauce ahead of time?
Yes, you can make the sauce up to two days in advance. Store it in the refrigerator and reheat gently before serving to keep it velvety and pourable.
How do I know when the cake is done baking?
Start checking at the 40-minute mark. Insert a toothpick into the center—if it comes out clean or with a few moist crumbs, your cake is ready. The top should be golden and the streusel crisp.
Is this Rhubarb Streusel Cake with Warm Vanilla Sauce Recipe suitable for special diets?
This recipe is vegetarian-friendly. For a dairy-free version, you can try using plant-based sour cream, milk, and butter alternatives, though the flavor and texture may vary slightly.
Final Thoughts
There’s something irresistibly nostalgic and heartwarming about baking the Rhubarb Streusel Cake with Warm Vanilla Sauce Recipe. Every slice is a celebration of simple, honest ingredients coming together in perfect harmony. Don’t be surprised if it becomes your new go-to for spring gatherings, Sunday brunches, or anytime you crave a little homemade comfort. Give it a try and let your kitchen fill with the scents (and smiles) that only a truly great cake can bring!
Print
Rhubarb Streusel Cake with Warm Vanilla Sauce Recipe
- Total Time: 1 hour 5 minutes
- Yield: 12 servings 1x
- Diet: Vegetarian
Description
This Rhubarb Streusel Cake with Warm Vanilla Sauce is a delightful spring dessert featuring a moist cake studded with tart rhubarb and topped with a spiced, buttery streusel. Served warm with a rich vanilla sauce, this old-fashioned American cake offers a perfect balance of tangy and sweet flavors, making it an irresistible treat for any occasion.
Ingredients
For the Cake:
- 2 cups all-purpose flour
- 1 teaspoon baking soda
- 1/2 teaspoon salt
- 1 cup granulated sugar
- 1 large egg
- 1 cup sour cream
- 1/3 cup vegetable oil
- 1 teaspoon vanilla extract
- 2 cups chopped fresh rhubarb
For the Streusel Topping:
- 1/2 cup brown sugar
- 1/2 cup all-purpose flour
- 1 teaspoon cinnamon
- 1/4 cup unsalted butter (cold and cubed)
For the Warm Vanilla Sauce:
- 1/2 cup granulated sugar
- 1/2 cup heavy cream
- 1/4 cup unsalted butter
- 1 tablespoon all-purpose flour
- 1/2 cup milk
- 1 teaspoon vanilla extract
Instructions
- Prepare the Cake Batter: Preheat your oven to 350°F (175°C) and grease a 9×13-inch baking dish. In a large bowl, whisk together the all-purpose flour, baking soda, salt, and granulated sugar to combine the dry ingredients evenly. In a separate bowl, beat the egg and mix in the sour cream, vegetable oil, and vanilla extract until smooth. Pour the wet ingredients into the dry mixture and stir gently until just combined to avoid overmixing. Fold in the chopped fresh rhubarb carefully to distribute evenly throughout the batter. Pour the batter into the prepared baking dish and smooth the top with a spatula.
- Make the Streusel Topping: In a small bowl, combine the brown sugar, all-purpose flour, and cinnamon. Add the cold, cubed unsalted butter and use a pastry cutter or two forks to cut the butter into the dry ingredients until the mixture resembles coarse crumbs. Sprinkle the streusel topping evenly over the cake batter, covering the surface completely to create a delicious crunchy layer after baking.
- Bake the Cake: Place the baking dish in the oven and bake for 40 to 45 minutes, or until a toothpick inserted into the center of the cake comes out clean. Bake until the cake is golden on top and the rhubarb is tender. Once done, remove it from the oven and let it cool slightly while preparing the sauce.
- Prepare the Warm Vanilla Sauce: In a small saucepan over medium heat, whisk together the granulated sugar, all-purpose flour, and milk until smooth. Add the heavy cream and unsalted butter, stirring constantly to prevent lumps. Cook the mixture for about 5 to 7 minutes, allowing it to simmer gently until it thickens slightly. Remove the saucepan from heat and stir in the vanilla extract to infuse the sauce with a fragrant vanilla flavor.
- Serve: Cut the cake into 12 slices and serve warm or at room temperature. Drizzle each serving generously with the warm vanilla sauce for a rich and comforting finish to this classic dessert.
Notes
- Frozen rhubarb can be used in place of fresh; just thaw and drain any excess liquid to prevent sogginess.
- The warm vanilla sauce can be made ahead of time and gently reheated before serving for convenience.
- Ensure not to overmix the batter to keep the cake tender and light.
- This cake is best served fresh but can be stored covered in the refrigerator for up to 2 days.
- Prep Time: 20 minutes
- Cook Time: 45 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 slice with sauce
- Calories: 370
- Sugar: 27g
- Sodium: 180mg
- Fat: 20g
- Saturated Fat: 11g
- Unsaturated Fat: 8g
- Trans Fat: 0g
- Carbohydrates: 42g
- Fiber: 1g
- Protein: 4g
- Cholesterol: 65mg