The Best Rhubarb Upside-Down Cake

There’s a magic in the way rhubarb’s tang elevates a cake: bright notes cut through richness, and its vibrant color becomes an edible statement. Thrive Market’s Rhubarb Olive Oil Cake embraces that balance. This upside-down style cake features a caramelized rhubarb topping that turns glossy and jewel-toned, while the batter beneath bakes soft and moist, thanks to the olive oil base.

While the standard recipe uses all-purpose flour and isn’t inherently gluten-free, this cake’s structure — relying on oil rather than butter, fruit over fat — suggests it could be adapted into a gluten-free dessert by substituting a certified gluten-free flour blend or almond flour combination. The recipe’s emphasis on whole ingredients, minimal layers, and depth of flavor make it an excellent target for such adaptation.

This cake is ideal for when you want dessert that feels elevated but not fussy. It works beautifully as a brunch sweet, dessert after dinner, or seasonal treat during rhubarb’s peak. The caramel-rhubarb top becomes the showpiece once inverted, and each slice reveals that vibrant pattern below.

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Rhubarb Upside-Down Cake

Recipe Details

Yield: 1 cake
Active Time: 15 minutes
Total Time: 1 hour

Rhubarb Upside-Down Cake Ingredients

For the caramel and rhubarb topping:

• 1/2 cup sugar
• 2 tablespoons water
• 2 tablespoons butter, cut into pieces
• 4 to 6 stalks rhubarb

For the cake:

• 1 3/4 cups all-purpose flour
• 1 cup sugar
• 1 1/2 teaspoons cardamom
• 1 teaspoon baking soda
• 1/4 teaspoon salt
• 2 eggs
• 3/4 cup orange juice
• 3/4 cup olive oil
• 2 teaspoons orange zest
• 1 teaspoon orange flower water (optional)

How to Make a Rhubarb Upside-Down Cake

1. Preheat oven to 350 degrees and line the bottom of a round springform cake pan with parchment paper.
2. Make the topping: Trim any bruised or leafy ends off the rhubarb and cut into pieces that will fit within the diameter of the cake pan.
3. Heat sugar and water in small saucepan over medium heat, scraping up any sugar from the bottom of the pan with a spatula. Bring to a boil, swirling occasionally, until caramel turns a dark amber color. This will take several minutes.
4. Quickly take off the heat, add butter, and stir. Put back on medium heat for a few seconds, stirring.
5. Quickly pour caramel into the prepared cake pan, tilting to evenly coat the bottom. Caramel will harden.
6. Arrange rhubarb slices in a decorative manner on top of caramel, to cover bottom.
7. Make the batter: In a large bowl, mix together flour, sugar, cardamom, baking soda, and salt.
8. In another bowl, whisk together eggs, oil, orange juice, zest and orange flower water.
9. Slowly pour the wet ingredients into the dry ingredients and stir until just mixed.
10. Bake the cake: Pour batter over rhubarb and bake for around 45 minutes, or until a toothpick comes out clean.
11. Allow to fully cool in pan, remove springform edge, and flip to reveal rhubarb pattern.

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Rhubarb Upside-Down Cake Nutrition Facts

*Estimated per slice (recipe yields 10 slices). Based strictly on Thrive Market’s ingredient amounts.

Serving Size	1 slice (1/10 of cake)
Calories	≈ 385 kcal
Protein	≈ 4 g
Carbs	≈ 50 g
Sugar	≈ 30 g
Fiber	≈ 1 g
Fat	≈ 20 g

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Rhubarb Upside-Down Cake Variations & Tips

• Gluten-free adaptation: Use a 1-to-1 gluten-free baking blend or a mix of almond flour + tapioca starch in place of regular flour.
• Fruit variations: Swap rhubarb for sliced strawberries, peaches, or a mix of berries for a similar effect.
• Flour tweak: Replace part of the flour with whole wheat pastry flour or spelt for subtle nuttiness.
• Spice accents: Add a pinch of cardamom, ginger, or cinnamon to the batter for complexity.
• Caramel layer control: Let the sugar-water caramel get a light amber — don’t overcook or it’ll burn after baking.
• Olive oil choice: Use a mild, buttery, or light olive oil to avoid overpowering flavor from strong olive notes.
• Slice method: Use a serrated knife and slice slowly downward to preserve the rhubarb topping rather than tearing it.
• Serve warm or room temperature: Warm slices tend to be softer; chilling slightly will help the cake set cleanly for slicing.

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Best Rhubarb Upside-Down Cake Pairings

• Whipped cream (dairy or plant-based): A dollop softens rhubarb tang and complements the caramel layer.
• Vanilla ice cream or coconut “nice” cream: Cool creaminess pairs beautifully with warm cake.
• Mascarpone or ricotta spread: Mildly tangy and creamy, perfect spread on top of slices.
• Fresh berries or berry compote: Adds brightness and contrasts the caramel sweetness.
• Light dessert wine or late harvest wine: Complements the sweet-tart profile of rhubarb.
• Fruit-forward herbal tea or a floral latte: Echoes the cake’s bright undertones and warms the palate.

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When to Make Rhubarb Upside-Down Cake

• Spring or early-summer dessert: Rhubarb’s peak season makes it ideal for seasonal menus.
• Brunch gatherings: Serves as a centerpiece dessert that’s pretty and shareable.
• Garden or tea parties: Elegant and visually striking cake for light afternoon settings.
• Holiday desserts: Adds variety to cookie and pie trays with a fruit-forward cake option.
• Birthday or special occasion cakes: Use as an alternative to traditional layer cakes for something unique.
• Weekend baking treat: A modest bake with flair—perfect when you have time and want something special.

Photo credit: Paul Delmont