This Rhubarb Cake with Butter Sauce is the kind of recipe that brings back memories of grandma’s kitchen: moist, tender cake with tart bursts of rhubarb and a golden butter sauce you’ll want to pour on everything. Whether served warm out of the oven or the next day reheated with extra sauce, it’s a timeless dessert that satisfies in every season.
It’s simple enough for a casual treat but elegant enough to serve at a spring brunch or family gathering. One bite, and you’ll understand why this cake’s a keeper.
Why I Love This Recipe
What makes this recipe a standout is the balance between tart rhubarb and the ultra-sweet, silky butter sauce. The buttermilk gives the cake a tender crumb, while the rhubarb keeps it moist and adds that signature zing. And that sauce? It’s like pouring liquid caramel-vanilla gold over every slice.
Bonus: it uses basic pantry ingredients, comes together easily, and tastes even better the next day—if it lasts that long.
Ingredients
For the Cake:
- 2 cups diced rhubarb (fresh or frozen, thawed and drained)
- 1 cup granulated sugar
- ½ cup unsalted butter, softened
- 1 large egg
- 1 tsp vanilla extract
- 1 cup buttermilk
- 2 cups all-purpose flour
- 1 tsp baking soda
- ½ tsp salt
For the Butter Sauce:
- ½ cup unsalted butter
- 1 cup granulated sugar
- ½ cup heavy cream
- 1 tsp vanilla extract
Swaps and Notes
- No buttermilk? Add 1 tbsp lemon juice or vinegar to 1 cup milk and let sit 5 minutes.
- Gluten-free option: Use a 1:1 gluten-free flour blend.
- Want extra tartness? Add a few chopped cranberries or raspberries to the batter.
- Prefer less sweetness? Use ¾ cup sugar in the cake and reduce sugar in the sauce to ¾ cup.
How to Make Rhubarb Cake with Butter Sauce
1. Preheat and Prep
- Preheat oven to 350°F (175°C).
- Grease and flour a 9×13-inch baking dish.
2. Make the Cake Batter
- In a large bowl, cream together the butter and sugar until light and fluffy.
- Add egg and vanilla, beating until smooth.
- In a separate bowl, whisk together flour, baking soda, and salt.
- Gradually add dry ingredients to the wet mixture, alternating with buttermilk, starting and ending with dry.
- Fold in the diced rhubarb.
3. Bake
- Pour the batter into the prepared baking dish and spread evenly.
- Bake for 45–50 minutes, or until a toothpick inserted into the center comes out clean.
- Let cool slightly in the pan.
4. Make the Butter Sauce
- In a saucepan, melt the butter over medium heat.
- Stir in the sugar and heavy cream, whisking constantly.
- Cook until smooth and lightly thickened, about 5–7 minutes.
- Remove from heat and stir in vanilla extract.
5. Serve
- Slice the cake warm or at room temperature.
- Drizzle with warm butter sauce just before serving.
- Optional: Top with whipped cream, vanilla ice cream, or even a sprinkle of cinnamon sugar.
Tips for Success
- Use fresh rhubarb when in season for the best flavor and color.
- Be sure to drain frozen rhubarb thoroughly to avoid a soggy batter.
- Want that golden crust? Sprinkle a little coarse sugar over the batter before baking.
- The cake stays moist for days—store covered at room temperature or refrigerate for longer freshness.
Serving Suggestions & Pairings
This rich, nostalgic cake pairs beautifully with these ChefManiac favorites:
- Big Family Banana Pudding to balance sweet-tart with creamy comfort
- Old-School No-Bake Cookies for a chewy, chocolatey contrast
- Caramel Apple Pie Cookies if you’re going for a rustic dessert spread
- No-Bake Oreo Cream Pie for something chilled to contrast the warm cake
- Chocolate Chip Cookie Bites as a snackable sweet side
Storage & Leftovers
- Room Temp: Store covered for up to 2 days.
- Fridge: Keeps well for up to 5 days.
- Freeze: Slice, wrap tightly, and freeze for up to 3 months (sauce separately).
- Reheat: Warm cake slices and sauce gently in the microwave before serving.
More Recipes You’ll Love
If you love classic desserts with a twist, try:
- Big Family Banana Pudding
- Old-School No-Bake Cookies
- No-Bake Oreo Cream Pie
- Caramel Apple Pie Cookies
- Chocolate Chip Cookie Bites
Final Thoughts
This Rhubarb Cake with Butter Sauce is a dessert that brings people back to the table. With its balance of tangy fruit and rich, buttery sweetness, it’s a must-bake when rhubarb is in season—or whenever you’re craving a taste of home. Pour on that sauce and dig in.
Tried it? Tag @ChefManiac and share your sweet-and-tart masterpiece! And follow for more classic bakes, seasonal treats, and desserts that taste like a warm hug.
