Rhubarb Upside Down Cake Recipe

Fresh from the oven, the top turns glossy and slightly jammy – a rhubarb cake that flips into something unexpectedly bright and buttery.

A quick moment before I even started

I didn’t plan on baking anything. I was just standing in the kitchen, poking at a bunch of rhubarb that looked a little too serious for its own good. It’s funny how it just sits there, all pink and sour, like it knows it’s underused. I kept thinking about that whole “rhubarb needs a better agent” idea. Honestly, fair. It deserves better gigs than just hanging out with strawberries all the time.

So I grabbed a pan. Not even the right one at first. Too big. I swapped it out halfway through prepping, which meant I had to scoop buttery sugar out and re-spread it. Not elegant. Still worked.

Rhubarb Upside Down Cake is a beautiful, no fuss dessert recipe that’s perfect for spring and summer. The kind that looks impressive even if you were a little distracted while making it. It’s got that sweet and tangy thing going on, with a soft, buttery cake underneath that soaks up everything happening on top. Or technically bottom. You get it.

Ingredients I Used for the Recipe

• 2 tablespoons unsalted butter (melted, for the base)
• 1/2 cup granulated sugar (to help caramelize the rhubarb)
• 1/4 cup brown sugar (adds a deeper, slightly sticky sweetness)
• 2 cups chopped rhubarb (the main character, tart and bright)
• 1 1/2 cups all purpose flour (structure, nothing fancy)
• 1 cup granulated sugar (for the cake batter)
• 2 teaspoons baking powder (for lift)
• 3/4 teaspoon salt (balances everything out)
• 6 tablespoons unsalted butter, room temp (makes the cake tender)
• 2/3 cup milk (keeps it soft and not dry)
• 1 teaspoon vanilla extract (rounds out the flavor)
• Zest of 1 small lemon (adds a fresh, sharp edge)
• 1 egg (holds it all together)

Something that almost ruined it

I almost forgot to grease the pan. Which is kind of ironic for something called an upside down cake. That flip at the end? Yeah, that’s where things can go wrong fast.

I caught it right before dumping in the rhubarb mixture. Gave it a quick swipe with butter, probably uneven, definitely rushed. Later, when I flipped the cake, one stubborn patch stayed stuck. I just scooped it out with a spoon and pressed it back on top. No one noticed. Honestly, it looked kind of intentional.

How to make Rhubarb Upside Down Cake?

Step 1 – Prep the pan and topping

Preheat the oven to 350°F. Grease an 8 inch round cake pan. Don’t skip this like I almost did. Mix the melted butter, 1/2 cup sugar, brown sugar, and chopped rhubarb in a bowl. It’ll look a bit loose and messy. That’s fine. Spread it across the bottom of the pan.

Step 2 – Start the batter

In a mixing bowl, combine the flour, remaining sugar, baking powder, and salt. I didn’t sift mine, just whisked aggressively. Add the butter in chunks, milk, vanilla, and lemon zest. Beat it for a couple minutes. It looks slightly uneven at first, like it’s not sure what it wants to be yet.

Step 3 – Add the egg and keep going

Crack in the egg and beat again for another two minutes. Mine still had tiny butter bits in it. I thought about fixing it, then didn’t. It bakes out fine. Better than fine.

Step 4 – Assemble

Pour the batter over the rhubarb layer. It won’t spread perfectly on its own, so I nudged it gently with a spoon. Try not to mix the layers too much.

Step 5 – Bake

Bake for about 45 to 50 minutes. I checked mine at 35 minutes and the top was already getting darker than I liked, so I loosely placed foil over it. Not tight. Just enough to calm it down.

Step 6 – The flip

Let it cool for about 5 minutes. Not longer, or it starts sticking more. Run a knife around the edge, place a plate on top, and flip it over in one confident move. Hesitation is where things go sideways. Lift the pan slowly. If something sticks, just fix it. No drama.

What it actually tasted like

Warm, slightly sticky on top, with that sharp rhubarb tang cutting through the sweetness. The edges get a little caramelized, almost chewy in spots. The cake itself is soft but not too fluffy. It has weight to it.

The lemon zest doesn’t scream “lemon,” but you’d notice if it wasn’t there. It keeps everything from feeling too heavy. I had a bite without anything on it, then another with a scoop of vanilla ice cream. The second one wins, obviously.

Also, the smell while it bakes? It’s not overly sweet. More buttery and slightly tart. It makes you check the oven more often than necessary.

Tips

• Use an 8 inch pan if you can. A larger one makes the cake thinner and it loses some of that soft center.
• If the top browns too fast, loosely cover with foil. Don’t seal it tight.
• Don’t wait too long before flipping. Around 5 minutes is the sweet spot.
• Frozen rhubarb works fine. I’ve used it straight from the freezer. No thawing.
• If a bit sticks to the pan, just patch it back. No one will care.
• Serve it warm. Cold is okay, but warm is where it actually shines.
• I sometimes reduce the sugar slightly if the rhubarb isn’t super tart. Depends on the batch.

Print Recipe

Rhubarb Upside Down Cake Recipe

Author: Kelsey Perez Cooking Method: Baking Cuisine: American Courses: Dessert

Difficulty: easy Prep Time 15 mins Cook Time 50 mins Rest Time 10 mins Total Time 1 hr 15 mins

Cooking Temp: 180  C Servings: 8 Estimated Cost: $ 5 Calories: 320

Best Season: Spring, Summer

Description

This rhubarb upside down cake is a simple yet stunning dessert that brings together a soft, buttery sponge with a vibrant sweet-tart rhubarb topping. As it bakes, the fruit caramelizes into a glossy layer that becomes the star once flipped. Perfect for spring and summer, this cake is easy to prepare and delivers a beautiful balance of flavors in every bite.

Ingredients

Servings

Rhubarb Topping

• 2 tbsp unsalted butter, melted
• ¹⁄₂ cup granulated sugar
• ¹⁄₄ cup brown sugar
• 2 cups chopped rhubarb (about 3–4 stalks)

Cake Batter

• 1 ¹⁄₂ cups all-purpose flour
• 1 cup granulated sugar
• 2 tsp baking powder
• ³⁄₄ tsp salt
• 6 tbsp unsalted butter (room temperature)
• ²⁄₃ cup milk
• 1 tsp vanilla extract
• 1 lemon zest
• 1 egg

Instructions

1. Preheat the oven to 180°C and grease an 8-inch round cake pan.
2. In a bowl, mix melted butter, 1/2 cup sugar, brown sugar, and chopped rhubarb until well coated.
3. Spread the rhubarb mixture evenly across the base of the prepared pan.
4. In a mixing bowl, combine flour, remaining sugar, baking powder, and salt.
5. Add butter, milk, vanilla extract, and lemon zest. Beat until smooth and creamy.
6. Add the egg and continue beating until fully incorporated.
7. Pour the batter over the rhubarb layer and spread evenly.
8. Bake for 45–50 minutes or until a toothpick inserted in the center comes out clean.
9. Let the cake cool for 5–10 minutes, then carefully invert onto a serving plate.
10. Serve warm, optionally with ice cream or whipped cream.

Nutrition Facts

Servings 8

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Amount Per Serving

Calories 320kcal

% Daily Value *

Total Fat 12g19%

Saturated Fat 7g35%

Cholesterol 45mg15%

Sodium 220mg10%

Potassium 150mg5%

Total Carbohydrate 48g16%

Dietary Fiber 2g8%

Sugars 30g

Protein 4g8%

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* Percent Daily Values are based on a 2,000 calorie diet. Your daily value may be higher or lower depending on your calorie needs.

Note

For best results, measure flour using the spoon-and-level method. Frozen rhubarb can be used without thawing. Store leftovers covered at room temperature for up to 2 days or refrigerate for up to 5 days.

Keywords: rhubarb cake, upside down cake, summer dessert, easy baking, fruit cake