Easy Rhubarb Cake with Tangy Sauce

This is the cake I make when spring shows up wearing a trench coat full of rhubarb like a very tart salesperson. It’s a soft, buttery snack cake that lets rhubarb be its gloriously tangy, dramatic self, plus a quick stovetop sauce that drips into every crumb like a rom-com finale. It’s special because it tastes like your grandma’s porch and a bakery had a baby—bright, not too sweet, and somehow still comforting. Also, it’s unfussy. Yes, there’s a sauce. No, you do not need a diploma to pour it over cake.

The first time I made this, my husband wandered in crunching on raw rhubarb like it was a celery stick and said, “It’s… zingy.” The kids used two stalks as lightsabers and whacked my cooling rack like they were rescuing the galaxy from dessert. I baked it in a pan that was clearly too small, because I love a gamble, and it puffed up like a couch cushion. Yes, this pan is too small. No, I won’t wash fewer dishes. The cake still came out perfect, the sauce did its tangy thing, and the smoke alarm only shrieked for, like, one verse.

Time-Saving Hacks

– Use frozen rhubarb straight from the bag—don’t thaw. The oven can babysit.
– Skip the mixer. Whisk like you mean it and call it arm day.
– Sauce shortcut: microwave it in bursts. Stir, zap, done. Slightly chaotic, perfectly effective.
– Line the pan with parchment so you can pretend you clean.
– Measure the sugar once for both cake and sauce—just scoop twice like a rebel.

Serving Ideas

– Warm slice + cold vanilla ice cream = people will think you planned ahead.
– Dollop with whipped cream, then pretend it’s “light” because fruit. Science!
– Greek yogurt on top if it’s “breakfast.” I don’t make the rules; I just ignore them.
– Coffee if you’re civilized. Wine if the kids played drums on the stock pots again.
– Eat it plain over the sink like a busy, mysterious icon.

What to Serve It With

– Brunch pals: crispy bacon, soft-scrambled eggs, and a bowl of strawberries.
– Afternoon snack: hot tea and sharp cheddar, because tart-sweet-salty is a power trio.
– After-dinner: a citrusy spritz or a small pour of prosecco to match the sparkle.

✔Tips & Mistakes

– Don’t peel rhubarb. You’ll lose color and gain regret. Just trim and chop.
– If your rhubarb is extra sour, toss it with a spoonful of sugar before mixing.
– Use a 9×9 or 8×8 pan with tall sides. The “cute” pan is a trap.
– Let the cake cool 10–15 minutes before saucing so it soaks in, not slides off.
– If the sauce looks thin, simmer 1–2 more minutes. It thickens as it cools—like me after snacks.

✔Storage Tips

Store it in the fridge… if there’s any left. Cold midnight leftovers? Sometimes better than fresh.
– Keeps 3–4 days covered. Sauce can be stored separately and reheated.
– Freeze slices without sauce up to 2 months; thaw and warm, then drizzle.

✔Variations and Substitutions

– Add strawberries to the sauce for classic pie vibes.
– Swap a little white sugar for brown in the cake for a caramel hint.
– Citrus kick: orange zest in the batter, lemon in the sauce.
– Almond extract instead of vanilla for a bakery-level flex.
– Gluten-free 1:1 flour works fine; so does dairy-free milk and oil instead of butter.
– Less sugar? Sure. More sugar? Also yes. I support your journey.

Frequently Asked Questions

Easy Rhubarb Cake with Tangy Sauce

Tender vanilla-scented rhubarb cake baked in a 9x13 pan and served with a bright, tangy orange–rhubarb sauce. Simple ingredients, big spring flavor.

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Prep Time: 20 minutes minutes

Cook Time: 45 minutes minutes

Total Time: 1 hour hour 5 minutes minutes

Servings: 12

Calories: 120kcal

Ingredients

 

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Main Ingredients

• ▢ 3 cups rhubarb, chopped for cake batter
• ▢ 1 cups granulated sugar for cake batter, divided
• ▢ 0.5 cups unsalted butter, softened
• ▢ 2 large eggs
• ▢ 1.5 teaspoons vanilla extract
• ▢ 2 cups all-purpose flour
• ▢ 2 teaspoons baking powder
• ▢ 0.5 teaspoons kosher salt
• ▢ 0.75 cups sour cream
• ▢ 0.5 teaspoons ground cinnamon optional
• ▢ 2 tablespoons powdered sugar for dusting, optional
• ▢ 2 cups rhubarb, chopped for tangy sauce
• ▢ 0.75 cups granulated sugar for sauce
• ▢ 0.5 cups orange juice freshly squeezed, for sauce
• ▢ 1 teaspoons orange zest, finely grated for sauce
• ▢ 0.25 cups water for sauce
• ▢ 1 tablespoons cornstarch for sauce
• ▢ 1 tablespoons cold water for cornstarch slurry
• ▢ 0.13 teaspoons kosher salt for sauce

Instructions

Preparation Steps

• Preheat oven to 350°F. Grease a 9x13-inch baking pan and line with parchment, leaving overhang for easy lifting.
• In a bowl, toss 3 cups chopped rhubarb with 0.25 cup of the 1 cup sugar. Set aside to macerate and release juices.
• In a large bowl, cream softened butter with the remaining 0.75 cup sugar until light and fluffy, 2 to 3 minutes. Beat in eggs one at a time, then mix in vanilla.
• Whisk flour, baking powder, salt, and cinnamon in a separate bowl.
• Add the dry ingredients to the butter mixture in two additions, alternating with the sour cream. Mix just until combined.
• Fold in the macerated rhubarb and any juices. Spread batter evenly into the prepared pan.
• Bake 40 to 45 minutes, until golden and a toothpick inserted in the center comes out clean. Cool in the pan for 15 minutes.
• Meanwhile, make the tangy sauce: In a saucepan, combine 2 cups chopped rhubarb, 0.75 cup sugar, orange juice, 0.25 cup water, orange zest, and 0.13 teaspoon salt. Bring to a gentle simmer over medium heat and cook 8 to 10 minutes, stirring occasionally, until rhubarb softens.
• Stir cornstarch with 1 tablespoon cold water to make a slurry. Slowly add to the simmering sauce, stirring constantly. Cook 1 to 2 minutes until thick and glossy. Remove from heat; sauce will thicken further as it cools.
• Serve warm slices of cake with warm or cooled tangy rhubarb sauce. Dust cake with powdered sugar if desired.

Notes

For cleaner slices, cool the cake completely and rewarm individual pieces as desired. If the sauce becomes too thick, thin it with a splash of orange juice or water just before serving.