Rhubarb Upside-Down Cake is a delightful way to celebrate spring and early summer produce. This cake features a vibrant layer of juicy rhubarb on top, a soft and fluffy vanilla cake in the middle, and a subtle crumb layer underneath for added texture. It’s the perfect combination of tart, sweet, and buttery flavors, making every slice irresistible.
A straight-on view of slices of the cake on a plate.
This dessert has been a favorite for years, and it’s easy to see why. Not only is it visually stunning when inverted, but it’s also a crowd-pleaser at gatherings, brunches, or just as a special treat at home. Its balance of tangy rhubarb, tender cake, and a crunchy base makes it truly unique.
Why You’ll Love This Rhubarb Cake
Tart Rhubarb – Rhubarb naturally softens and becomes juicy during baking, creating a bright, flavorful topping. Its tang balances the sweetness of the cake beautifully.
Light Vanilla Cake – The cake itself is fluffy, moist, and slightly sweet. It serves as the perfect canvas for the rhubarb without overwhelming it.
Crunchy Crumb Layer – Hidden at the bottom, the crumb layer adds a subtle crunch. This little surprise makes the cake more exciting and adds depth to each bite.
A slice of rhubarb cake on a plate, garnished with whipped cream.
Ingredients Overview
Here’s a quick look at what you’ll need for this cake. Full measurements are included in the recipe card below.
Rhubarb – Fresh, firm stalks are key. You can find rhubarb in grocery stores or at local farmers’ markets during the spring and summer. Color can range from green to deep red, but any firm stalk will work.
Flour – Use all-purpose flour for best results. Spoon and level the flour when measuring to avoid a dense cake.
Eggs – Large eggs at room temperature help create a stable and airy cake.
Dairy – Full-fat sour cream and butter add richness and moisture. Milk (2%) rounds out the batter.
Sugar – Granulated sugar sweetens the rhubarb layer and the cake. Brown sugar in the crumb layer gives a hint of caramelized flavor.
Ingredient Substitutions
Dairy-Free – Swap butter, milk, and sour cream with trusted dairy-free alternatives.
Greek Yogurt – Full-fat Greek yogurt can replace sour cream if desired.
Other Fruits – Strawberries, raspberries, or a mix of berries can be added for variation.
Step-by-Step Instructions
Follow these steps to make your Rhubarb Upside-Down Cake perfectly.
Step 1: Prepare the Rhubarb
Chop the rhubarb into 1-inch pieces and mix with sugar. Let the mixture sit while you prepare the batter to release natural juices.
A bowl of the rhubarb mixture.
Step 2: Make the Crumb Layer
In a small bowl, combine melted butter, sugar, flour, a pinch of cinnamon, and a little salt. Stir until crumbly and set aside.
A bowl of crumb topping mixture.
Step 3: Prepare the Cake Batter
Cream softened butter and sugar together until light and fluffy. Add eggs, beating until combined. Mix in vanilla and sour cream.
Combine flour, baking powder, and salt separately, then gradually fold into the wet ingredients along with milk. Mix on low speed until just incorporated—overmixing will make the cake dense.
The cake batter in a bowl.
Step 4: Assemble the Cake
Grease a 9-inch cake pan generously with butter. Scatter chunks of butter across the bottom and arrange the rhubarb on top. It doesn’t have to be perfect—the charm is in its rustic look.
The rhubarb layer in the cake pan.
Step 5: Add Batter and Crumb Layer
Pour the cake batter over the rhubarb, spreading it evenly. Sprinkle the crumb topping over the batter.
The batter spread in the pan with crumb topping on top.
Step 6: Bake
Bake in a preheated 350°F oven for 45–55 minutes. Insert a toothpick to check doneness; it should come out with moist crumbs, not wet batter.
Let the cake cool in the pan for 10 minutes before inverting onto a cooling rack with a baking sheet underneath to catch any rhubarb juices.
Baked rhubarb cake in the pan.
Serving and Storing
Allow the cake to cool completely before slicing. A tip for serving: add a dollop of freshly whipped cream or a light dusting of powdered sugar for extra indulgence. The contrast of creamy topping with tart rhubarb is delightful.
Storage Tips:
- At room temperature: Keep the cake in an airtight container for up to 3 days.
- In the fridge: Cover well and store for up to 6 days. This helps maintain moisture, especially if your kitchen is warm.
Expert Tips for Success
Oven Thermometer: Many ovens run hotter or cooler than the dial indicates. An oven thermometer ensures you’re baking at the correct temperature, which is key to a fluffy, even cake.
Kitchen Scale: Measuring flour by weight guarantees consistency. Spoon-and-level methods can vary, but using a scale ensures the cake turns out perfectly every time.
Inverting the Cake: When turning the cake out of the pan, do it carefully and place a baking sheet underneath to catch any juices. If the rhubarb sticks, gently tap the pan to release it.
A slice of rhubarb cake topped with whipped cream on a plate.
Frequently Asked Questions
How do I pick good rhubarb? Look for firm, crisp stalks with bright color. Avoid stalks that are wilted or soft.
Can I eat rhubarb leaves? No, rhubarb leaves are toxic and should never be consumed.
Can I freeze rhubarb? Yes! Chop and freeze rhubarb in an airtight bag. It can be used later for baking or sauces.
When is rhubarb in season? Spring through early summer is peak rhubarb season.
Where can I buy rhubarb? Farmers’ markets are ideal, but grocery stores often carry it during its season.
Recipe Variations
Strawberry Rhubarb Cake: Swap half of the rhubarb for fresh strawberries. The sweetness of strawberries balances the tang of rhubarb beautifully.
Citrus Twist: Substitute lemon zest and juice if orange isn’t available. Either option adds a bright, refreshing note to the cake.
Other Fruit Options: Rhubarb pairs well with raspberries, blueberries, or even a small amount of pineapple for a tropical twist.
Special Tools
Cake Pans: A 9-inch cake pan is ideal. Using quality pans ensures even baking and easy release of the cake.
Offset Spatula: Makes spreading batter and toppings easy and precise. It’s a simple tool that makes a big difference when assembling the cake.
A top-down view of the rhubarb cake, with dollops of whipped cream on slices.
- Preheat oven to 350°F. Butter a 9-inch cake pan thoroughly and line with parchment if desired. Scatter 4 tbsp butter chunks across the bottom.
- Mix rhubarb and sugar; let sit while preparing the batter.
- Cream butter and sugar in a large bowl until fluffy. Add eggs, then vanilla, orange zest, and juice. Mix in sour cream.
- Combine flour, baking powder, and salt separately. Fold into wet ingredients, then add milk slowly until just combined.
- Spread rhubarb in pan, pour batter over rhubarb, then sprinkle crumb mixture on top.
- Bake for 45–55 minutes. Insert a toothpick—it should come out with moist crumbs. Cool 10 minutes in pan, then invert onto cooling rack with a sheet beneath. Let cool before slicing.
Notes
- Ensure butter and eggs are at room temperature for best texture.
- Do not overmix batter to keep the cake light and fluffy.
- For extra flavor, try a splash of vanilla or almond extract in the batter.