Strawberry Rhubarb Upside-Down Cake is the kind of dessert I make when I want a real fruit dessert but still want cake. The top turns into a sticky strawberry-rhubarb layer with caramel edges, and the cake underneath stays soft and tender.
My take is a vanilla buttermilk cake with a little sour cream for a moist crumb. The sweet brown sugar topping plays really well with rhubarb’s tart bite, and the strawberries soften into a jammy layer.
I like serving this slightly warm, sliced thick, with whipped cream or vanilla ice cream. It’s especially good in late spring and summer when strawberries are at their best.
Why You’ll Love This Recipe
Showy but simple: It looks like you fussed, but it’s really just a cake you flip over at the end.
That caramelized fruit top: The brown sugar and butter turn the strawberries and rhubarb glossy and sticky in the best way.
Tender vanilla cake: The buttermilk and sour cream keep the crumb soft, even after it cools.
Balanced sweetness: Rhubarb keeps the topping from tasting flat or too sugary, which I really prefer in fruit cakes.
Easy to serve: It slices cleanly once it sits for a bit, and it doesn’t need frosting or extra decorating.
Ingredients You’ll Need
Fruit topping
- Unsalted butter: This is what makes the brown sugar melt into that sticky caramel layer. I stick with unsalted so the salt level stays in my control.
- Light brown sugar: Packed brown sugar gives the topping that deep caramel flavor. Dark brown sugar works too if you like it a little stronger.
- Rhubarb: Slice it evenly so it cooks at the same rate. If your rhubarb is very thick, keep the pieces closer to the smaller side.
- Strawberries: Fresh is best here. If they’re giant, cut into quarters so they don’t release too much juice all at once.
- Lemon juice: Brightens the fruit and keeps the topping tasting fresh instead of heavy.
- Cornstarch: Helps the fruit juices thicken up so the topping isn’t runny. If your fruit is extra juicy, adding a little more is worth it.
- Salt: Just a pinch in the fruit makes the whole topping taste more balanced.
Cake batter
- All-purpose flour: Regular flour is perfect here. I don’t recommend swapping in cake flour unless you bake with it a lot and know how it behaves.
- Baking powder: This gives the cake most of its lift so it bakes up light.
- Baking soda: A small amount helps the buttermilk do its thing and keeps the crumb tender.
- Fine salt: Don’t skip it. Cake can taste flat without enough salt, especially with sweet toppings.
- Unsalted butter: Softened butter creams better and gives you a nicer texture than melted butter in the batter.
- Granulated sugar: Keeps the cake light and clean-tasting under the fruit layer.
- Eggs: Room temperature eggs mix in more smoothly, which helps the batter stay even.
- Vanilla extract: This is a vanilla-forward cake, so use a vanilla you actually like the taste of.
- Buttermilk: Gives that slight tang and helps keep the cake soft. If you don’t have it, milk with a splash of vinegar works fine.
- Sour cream or plain yogurt: This adds moisture and a little richness. I use full-fat when I have it, but any plain yogurt works.
Recipe Instructions
- Preheat the oven: Heat the oven to 350°F. Grease a 9-inch round metal cake pan, line the bottom with parchment, then grease the parchment too.
- Melt the butter: Melt the butter for the topping and pour it into the prepared pan. Tilt the pan a bit so the butter coats the bottom evenly.
- Add the brown sugar: Sprinkle the brown sugar evenly over the melted butter to form a full layer.
- Mix the fruit: Toss the rhubarb and strawberries with the lemon juice, cornstarch, and a pinch of salt, then spread the fruit evenly over the brown sugar layer.
- Mix the dry ingredients: Whisk the flour, baking powder, baking soda, and fine salt together in a medium bowl.
- Cream the butter and sugar: Beat the softened butter and granulated sugar until light and fluffy.
- Add the eggs and vanilla: Beat in the eggs one at a time, then mix in the vanilla extract.
- Add the flour and buttermilk: Mix in the dry ingredients in two additions, alternating with the buttermilk, and mix just until you no longer see dry flour.
- Mix in the sour cream: Add the sour cream (or yogurt) and mix just until combined.
- Add the batter: Spoon the batter over the fruit, then gently spread it to the edges so the fruit is covered.
- Bake: Bake for 40 to 50 minutes, until the top is golden and a toothpick inserted into the cake portion comes out clean.
- Cool and invert: Let the cake cool in the pan for 10 minutes, run a knife around the edge, then invert onto a plate. Peel off the parchment and let it cool about 15 minutes before slicing.
Some of my tips!
This is the part that really makes a difference. If you only read one section, make it this one because this is where I share the little trick that helps the recipe turn out so well.
Recipe Tips & Tricks
Use a metal cake pan. Metal browns the topping better and gives you that caramelized edge. I’d skip a springform pan here because the butter and sugar can leak.
Line the bottom with parchment. Even though it’s upside-down cake, parchment makes the flip less stressful. It also helps keep the fruit layer intact.
Watch the fruit’s juiciness. Some strawberries throw off a lot of liquid, and rhubarb can vary too. If your fruit looks extra juicy, add another teaspoon of cornstarch so the topping sets up nicely.
Don’t overmix the batter. Once the flour goes in, mix just until it comes together. Overmixing makes the cake tougher and less tender.
Flip while it’s still warm. Let it cool in the pan for the 10 minutes, then invert it. If it sits too long, the topping can stick more.
Make some touches!
There are plenty of easy ways to serve this depending on the occasion. Keep it simple, or add a few small touches to make it feel a little more special.
Serving Suggestions
- Whipped cream: A soft dollop on each slice is simple and classic. I like it best when the cake is still a little warm.
- Vanilla ice cream: This is my favorite option if you want it to feel like a real dessert-dessert. The cold ice cream with the warm fruit top is hard to beat.
- Extra berries: A few fresh strawberries on the side make the plate look nice and add something fresh. If you have them, raspberries work too.
- Coffee or tea: This is a great afternoon cake with coffee, or with black tea if you want something lighter.
Save it for later
This section covers how to store leftovers and what parts of the recipe you can prepare ahead of time.
Storage and Make Ahead
Store leftovers covered in the fridge for up to 4 days. I usually keep it right on the serving plate and cover it well so the cake doesn’t dry out.
To serve again, I like warming individual slices briefly in the microwave. You can also warm slices in a low oven if you’re serving a few people at once.
You can make this recipe ahead and serve it the next day. The topping softens a bit as it sits, but the flavor is still great.
If you want it to last longer, you can freeze individual portions and thaw in the fridge overnight. The fruit layer will be a little softer after thawing, but it still eats well.
A few quick answers
This section covers a few extra details that may help before you head to the recipe card.
Recipe FAQs
Can I use frozen strawberries or frozen rhubarb?
You can, but expect more liquid. Use the extra teaspoon of cornstarch, and don’t thaw the fruit fully before mixing it with the lemon juice and cornstarch or it can get very watery fast.
What can I use instead of buttermilk?
Milk plus about 1 1/2 teaspoons vinegar works well here. Stir it together and let it sit for a few minutes, then use it like buttermilk.
How do I know when the cake is done?
The top should be golden and spring back lightly when you touch it. I also check with a toothpick in the cake part (not down in the fruit layer) and look for it to come out clean.
Why did my topping stick to the pan?
Usually it’s because the pan wasn’t greased well enough or the cake cooled too long before flipping. I’d suggest using parchment on the bottom and flipping after the 10-minute cool time.
Can I bake this in a cast iron skillet?
Yes, a 9-inch cast iron skillet works well and caramelizes nicely. Just keep an eye on the bake time since skillets can run a little hotter than a cake pan.
You might also like
Before you go, take a look at a few other recipes below the recipe card. They use similar ingredients in a different way and are worth saving too.
MORE DINNER RECIPES TO TRY
Strawberry Rhubarb Upside-Down Cake
INGREDIENTS
Fruit topping
- 4 tbsp unsalted butter
- 3/4 cup packed light brown sugar
- 2 cups rhubarb sliced 1/2 inch
- 2 cups strawberries hulled and halved
- 1 tbsp lemon juice
- 1 tsp cornstarch
- pinch salt.
Cake batter
- 1 1/2 cups all purpose flour
- 1 1/2 tsp baking powder
- 1/4 tsp baking soda
- 1/2 tsp fine salt
- 1/2 cup unsalted butter softened
- 3/4 cup granulated sugar
- 2 large eggs room temperature
- 2 tsp vanilla extract
- 1/2 cup buttermilk room temperature
- 2 tbsp sour cream or plain yogurt.
INSTRUCTIONS
Pan and topping
- Heat oven to 350 F and grease a 9 inch round cake pan then line bottom with parchment and grease again
- melt 4 tbsp butter and pour into pan then sprinkle evenly with brown sugar
- toss rhubarb and strawberries with lemon juice cornstarch and pinch salt then spread evenly over the sugar layer.
Batter and baking
- Whisk flour baking powder baking soda and salt
- beat softened butter and granulated sugar until light then beat in eggs one at a time and mix in vanilla
- mix in dry ingredients in two additions alternating with buttermilk and finish by mixing in sour cream until just combined
- spoon batter over fruit and gently spread to edges
- bake until golden and a toothpick in the cake portion comes out clean 40 to 50 minutes
- cool in pan 10 minutes then run a knife around edge and invert onto a plate and peel off parchment
- cool 15 minutes before slicing.
