Upside-Down Rhubarb Cake with Caramel Swirls

Every spring when rhubarb starts to pop up in gardens and farmers markets, I feel a flutter of excitement. This Upside-Down Rhubarb Cake with Caramel Swirls is my go-to treat for showcasing rhubarb's tart, tangy flavor wrapped in sweet, buttery cake. It's a recipe that started as an experiment and quickly became a seasonal favorite in our family.

When my kids see the bright stalks of rhubarb arrive in our kitchen, they know a special dessert is on the way. There's something magical about the way the vibrant pink turns tender and jammy during baking. The smell of caramel bubbling away on the stove, blending with the earthy sweetness of rhubarb, makes our whole home feel cozy and inviting.

Perfect for brunches, afternoon tea, or a stunning spring dessert, this cake combines rich caramel, soft rhubarb, and tender vanilla cake in every bite. It’s as pretty as a picture right out of the pan and fills your kitchen with the scent of spring. Whether you're a seasoned baker or a weekend dabbler, this recipe is simple, rewarding, and sure to win hearts.

Why You’ll Love Upside-Down Rhubarb Cake with Caramel Swirls

• Sweet & Tart Combo: The tangy rhubarb and sweet caramel balance each other beautifully for a satisfying bite.
• Seasonal Star: A wonderful way to enjoy rhubarb at its peak, especially if you grow it in your garden.
• Showstopper Appearance: The rhubarb pattern on top is effortlessly elegant and creates a stunning centerpiece.
• Moist Texture: Thanks to sour cream and milk, the crumb is soft and rich without being heavy.
• Perfect for Any Occasion: Serve it at brunch, Mother's Day, spring picnics, or a casual family gathering.
• Caramel Heaven: The buttery caramel layer adds depth and decadence.
• Make-Ahead Friendly: Stays moist for days and can be made the night before.

Ingredients You’ll Need

For the Caramel Rhubarb Layer:

• ½ cup brown sugar – Light or dark brown both work, depending on how deep you want the caramel flavor.
• ¼ cup unsalted butter – Rich and creamy, it creates the caramel base.
• 2 tablespoons heavy cream – Adds silkiness to the caramel.
• 2 cups fresh rhubarb, chopped – Choose stalks that are firm and brightly colored. Cut into ½-inch pieces.

For the Cake Batter:

• 1 ½ cups all-purpose flour – Spoon and level to avoid a dense cake.
• 1 teaspoon baking powder – Ensures a light rise.
• ½ teaspoon baking soda – Reacts with sour cream for added lift.
• ¼ teaspoon salt – Enhances flavor and balances sweetness.
• ½ cup unsalted butter, softened – Make sure it's room temperature for proper creaming.
• ¾ cup sugar – Granulated sugar gives a light, sweet flavor.
• 2 large eggs – Room temperature eggs incorporate better and help the cake rise.
• 1 teaspoon vanilla extract – Adds classic flavor and warmth.
• ½ cup sour cream – Keeps the cake incredibly moist and adds a slight tang.
• ¼ cup milk – Thins the batter to the perfect pouring consistency.

Step-by-Step Instructions

1. Preheat and Prepare Pan:
   • Preheat your oven to 350°F (175°C).
   • Grease a 9-inch round cake pan with butter or cooking spray.
   • Line the bottom with parchment paper to prevent sticking.
2. Make the Caramel Base:
   • In a small saucepan over medium heat, combine the brown sugar, butter, and heavy cream.
   • Stir constantly until the mixture is smooth and starts to bubble gently, about 3-4 minutes.
   • Immediately pour the caramel into the bottom of the prepared pan and spread evenly with a spatula.
   • Evenly scatter the chopped rhubarb on top of the caramel. Try to cover as much of the surface as possible for even topping.
3. Mix Dry Ingredients:
   • In a medium bowl, whisk together the flour, baking powder, baking soda, and salt.
   • Set aside.
4. Cream Butter and Sugar:
   • In a large bowl or stand mixer, beat the softened butter and sugar together until light and fluffy, about 2-3 minutes.
   • Scrape down the sides of the bowl as needed.
5. Add Eggs and Vanilla:
   • Beat in the eggs one at a time, ensuring each is fully incorporated before adding the next.
   • Stir in the vanilla extract.
6. Combine Wet and Dry:
   • Mix in the sour cream until smooth.
   • Add the dry ingredients in three parts, alternating with the milk, beginning and ending with the dry. Mix just until no streaks remain.
7. Assemble and Bake:
   • Carefully spoon the batter over the rhubarb and caramel layer. Use a spatula to smooth the top.
   • Tap the pan lightly on the counter to remove air bubbles.
   • Bake for 40-50 minutes, or until the top is golden and a toothpick inserted into the center comes out clean.
8. Cool and Invert:
   • Let the cake cool in the pan for 10-15 minutes. Do not rush this step or the caramel may stick.
   • Run a knife around the edge of the pan to loosen the cake.
   • Place a serving plate over the cake and carefully invert it.
   • Remove the pan and peel away the parchment paper.

Serving and Storage Tips

• Serve: This cake is best enjoyed slightly warm or at room temperature. Top with whipped cream, ice cream, or a drizzle of extra caramel for added decadence.
• Store: Store covered at room temperature for up to 2 days. For longer storage, refrigerate in an airtight container for up to 5 days.
• Freeze: Wrap individual slices in plastic wrap and place in a freezer-safe bag. Freeze for up to 2 months. Thaw overnight in the fridge or reheat gently in the microwave.
• Transport Tip: If taking to a gathering, bring the cake in the pan and invert it at your destination for best results.

Helpful Notes

• Use Fresh Rhubarb: While frozen rhubarb is convenient, fresh rhubarb yields the best texture. If using frozen, thaw and drain well.
• Spice It Up: Add a dash of cinnamon, cardamom, or nutmeg to the batter for extra depth.
• Zesty Twist: A teaspoon of orange zest in the batter complements the rhubarb beautifully.
• Caramel Swirl Tip: Drizzle a bit of extra caramel into the batter before baking for pockets of gooey sweetness.
• Pan Size: You can use an 8-inch pan, but extend baking time slightly and watch for doneness.

Frequently Asked Questions

1. Can I use frozen rhubarb?
   Yes, but thaw it completely and drain off excess liquid to prevent sogginess.
2. Can I use a different fruit?
   Absolutely! Try swapping in strawberries, raspberries, or even chopped apples or pears.
3. Do I need to refrigerate the cake?
   Not immediately. It’s fine at room temperature for up to 2 days. After that, refrigerate to maintain freshness.
4. What if I don't have sour cream?
   Greek yogurt makes a great substitute with a similar tang and moisture content.
5. Can I make it ahead?
   Yes! Make it a day in advance and store covered at room temperature. The flavors deepen beautifully overnight.
6. How do I stop the cake from sticking?
   Always line the pan with parchment paper and let the cake cool slightly before inverting.

Final Thoughts

Upside-Down Rhubarb Cake with Caramel Swirls is a celebration of spring's bounty in cake form. It’s comforting, gorgeous, and utterly delicious. Whether you're baking it for a weekend treat or sharing it at a springtime get-together, this cake is sure to bring smiles and compliments.

From the buttery caramel glaze to the soft rhubarb topping and rich vanilla crumb, every bite is a taste of home-baked happiness. Try it once, and it might just become your new spring tradition. If you do bake it, I’d love to see your creations—tag me on social media or leave a comment below. Happy baking!

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