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This rich and buttery Rhubarb Upside Down Cake is the perfect way to celebrate rhubarb season. A caramelized topping of tart rhubarb and crunchy walnuts sits atop a moist, tender cake that’s good enough to have you going back for a second slice. Or a third.
I’ve made this rhubarb upside down cake many times now, and every time it turns out just as delicious as the last. After plenty of testing and tweaking, I can say with confidence this is the kind of cake you’ll crave all spring and summer long.
Why You’ll Love This Rhubarb Upside Down Cake
Similar to my Upside Down Cranberry Coffee Cake, a good upside down cake strikes the perfect balance between tart fruit, buttery topping, and tender crumb. This recipe nails it.
- Caramelized Rhubarb and Walnuts: A simple brown sugar and butter mixture creates a bubbling, sticky topping that perfectly balances the tart rhubarb.
- Moist Sour Cream Cake: The cake itself is buttery, soft, and just lightly sweet, letting the topping shine. It has a similar texture to my Sour Cream Coffee Cake.
- Flexible and Forgiving: Don’t love walnuts? Leave them out. Want it even sweeter? Serve it with a dollop of whipped cream.
Exact ingredient quantities are listed in the recipe card below. Note: the recipe card allows you to easily scale the recipe and will automatically adjust the ingredient amounts.
Key Ingredients and Why They Matter
The magic of this cake comes from a few carefully chosen ingredients.
- Fresh Rhubarb: Its tartness cuts through the richness of the cake, keeping every bite bright and lively.
- Brown Sugar and Butter: This classic combination melts into a rich caramel that coats the rhubarb and walnuts. I use a similar syrup for my Pineapple Upside Down Cake and Banana Upside Down Cake recipes.
- Sour Cream: It gives the cake a tender crumb and just the right amount of moisture without making it heavy.
- Walnuts: Their crunch adds texture to contrast with the soft cake, but feel free to omit them if you prefer.
How to Make Rhubarb Upside Down Cake
You’ll be amazed at how easily this showstopping dessert comes together. The full recipe is below, but here is a quick summary.
- Prepare the Topping: In a saucepan, melt the brown sugar and butter. Bring it to a boil, then stir in the chopped rhubarb and walnuts. Pour this mixture into a foil-wrapped springform pan.
- Make the Cake Batter: Cream together the butter and sugar until fluffy. Beat in the eggs and vanilla, then alternately add the dry ingredients and sour cream until the batter is smooth.
- Assemble and Bake: Gently spread the batter over the rhubarb topping. Bake until a toothpick comes out clean, about 60 minutes. Let it cool briefly, then carefully invert onto a serving platter.
Tips for the Best Rhubarb Upside Down Cake
- Use Fresh Rhubarb: The tartness is essential for balancing out the sweet, buttery topping. It is typically in season late spring to early summer. I always buy a ton so that I can also make my popular Strawberry Rhubarb Jam.
- Foil Your Pan: Springform pans can leak, especially with caramel on the bottom. Wrapping the outside tightly with foil prevents a mess in your oven.
- Don’t Overcook the Topping: You want it just melted and combined before pouring into the pan, otherwise it can harden too quickly.
- Check Doneness with a Thermometer: The cake is ready when the center reads between 200-210°F.
Serving Suggestions
This rhubarb upside down cake is wonderful all on its own, but even better served slightly warm with a dollop of:
- Lightly sweetened whipped cream
- A scoop of vanilla ice cream
- A drizzle of heavy cream
No matter how you serve it, it’s bound to disappear quickly!
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Equipment
- 9-inch springform pan
Ingredients
Topping:
- 2/3 cup brown sugar packed
- 1/2 cup butter
- 2 cups fresh rhubarb chopped
- 3/4 cup walnuts chopped
Cake:
- 1/2 cup butter room temperature
- 3/4 cup white sugar
- 2 eggs
- 1 teaspoon vanilla extract
- 1 cup sour cream
- 1 1/2 cups all-purpose flour
- 1 1/2 teaspoons baking powder
- 1 teaspoon baking soda
- 1/4 teaspoon salt
Instructions
- Preheat oven to 350℉. Wrap the outside of a 9-inch springform pan with aluminum foil to prevent leaking, because it will leak. Sift together the 1 1/2 cups all-purpose flour, 1 1/2 teaspoons baking powder, 1 teaspoon baking soda, and 1/4 teaspoon salt. Set aside.
- In a saucepan over medium heat, combine 2/3 cup brown sugar and 1/2 cup butter. Bring to a boil, then add 2 cups fresh rhubarb and 3/4 cup walnuts (if using), stir, and pour into bottom of springform pan. Do not overcook the sugar mixture.
- In a large bowl, cream together the 1/2 cup butter and 3/4 cup white sugar until light and fluffy. Beat in the 2 eggs one at a time, then stir in the 1 teaspoon vanilla extract. Beat in the flour mixture alternately with the 1 cup sour cream. Pour batter into the prepared pan.
- Bake in the preheated oven for 60 minutes, or until a toothpick inserted into the center of the cake comes out clean. The internal temperature of the cake should reach 200-210°F when it's fully baked. Using an instant-read thermometer inserted into the center of the cake (avoiding the bottom of the pan) is the most reliable way to check for doneness. Cool in the pan for 10 minutes, then invert onto serving platter and carefully release ring and remove pan. Serve warm with whipped cream, if desired.
Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
Delicious – my family loved it. We will make it again soon, thank you!
I don’t bake with rhubarb often, and this recipe changed my mind. So delicious and such a great treat!
This was soooo good!