Rhubarb Dump Cake: Easy 5-Ingredient Dessert
There’s something magical about a dessert that requires zero mixing and delivers maximum flavor. This rhubarb dump cake is exactly that—a beautifully simple recipe that transforms tart rhubarb into a warm, buttery masterpiece.
With just five ingredients and minimal prep, you’ll have a crowd-pleasing dessert that tastes like it took hours. The tangy rhubarb pairs perfectly with a sweet cake topping, creating an irresistible contrast in every bite.
Whether you’re using fresh garden rhubarb or frozen stalks from the store, this foolproof recipe works every time. It’s the ultimate spring and summer dessert that feels both rustic and special.
What Is Rhubarb Dump Cake?
A dump cake is a vintage American dessert where you literally dump ingredients into a pan without mixing. The result is a cobbler-like treat with a crispy, golden top and a soft, fruity base.
Rhubarb dump cake features chopped rhubarb as the star ingredient, layered with cake mix and butter. As it bakes, the butter melts through the dry mix, creating pockets of cake batter that bake into a delicious crust.
The beauty of this recipe is its flexibility—you can swap rhubarb for other fruits or add mix-ins. But the classic rhubarb version remains a springtime favorite for its perfect balance of tart and sweet.
Why You’ll Love This Recipe
Minimal effort, maximum reward. You don’t need a mixer, bowls, or any fancy equipment. Just layer, bake, and enjoy a dessert that looks and tastes impressive.
Perfect for rhubarb season. This recipe is an excellent way to use up an abundance of rhubarb. The tartness of the rhubarb shines through while the cake mix adds just enough sweetness.
Crowd-pleaser for any occasion. Serve it warm with vanilla ice cream for a casual weeknight treat, or bring it to potlucks and gatherings. It’s always a hit.
Ingredients You’ll Need
The beauty of rhubarb dump cake lies in its simplicity. Here’s what you’ll need:
If using frozen rhubarb, there’s no need to thaw it first. The extra moisture actually helps create a saucier base.
Read More: Cranberry Pecan Cheesecake Ball
How to Make Rhubarb Dump Cake
This recipe comes together in minutes. Start by preheating your oven to 350°F and greasing a 9×13-inch baking dish.
Spread the chopped rhubarb evenly across the bottom of the pan. Sprinkle sugar over the rhubarb—this helps draw out the juices and balance the tartness.
Pour the dry cake mix evenly over the sugared rhubarb. Don’t mix or stir—just create an even layer. Drizzle melted butter over the entire surface, making sure to cover as much of the cake mix as possible for maximum crispiness.
Bake for 45-50 minutes until the top is golden brown and the rhubarb is bubbling around the edges. Let it cool for 10 minutes before serving warm.
Rhubarb Dump Cake: Easy 5-Ingredient Dessert
Course: Dessert12
servings10
minutes50
minutes1
hourIngredients
4 cups fresh or frozen rhubarb, chopped into ½-inch pieces
1 cup granulated sugar
1 box (15.25 oz) yellow cake mix
¾ cup (1½ sticks) unsalted butter, melted
Optional: 1 teaspoon vanilla extract
Directions
- Preheat oven to 350°F (175°C). Grease a 9×13-inch baking dish with butter or cooking spray.
- Layer the rhubarb: Spread chopped rhubarb evenly across the bottom of the prepared pan.
- Add sugar: Sprinkle granulated sugar evenly over the rhubarb layer.
- Add cake mix: Pour the dry cake mix evenly over the sugared rhubarb. Do not mix or stir—just spread it into an even layer.
- Drizzle butter: Pour melted butter evenly over the entire surface of the cake mix, covering as much as possible.
- Bake: Place in preheated oven and bake for 45-50 minutes, until the top is golden brown and rhubarb is bubbling around the edges.
- Cool and serve: Let cool for 10 minutes before serving warm with vanilla ice cream or whipped cream.
Notes
- Frozen rhubarb: No need to thaw—use directly from frozen. Baking time may increase by 5 minutes.
Sweetness adjustment: If your rhubarb is very tart, increase sugar to 1¼ cups.
Butter coverage: The more evenly you distribute the butter, the crispier your topping will be.
Cake mix flavor: Vanilla, white, or butter cake mix work beautifully as alternatives to yellow.
| Nutrient | Per Serving |
|---|---|
| Calories | 288-340 kcal |
| Total Fat | 9-14 g |
| Sugars | 15-43 g |
| Protein | 2-3 g |
| Dietary Fiber | 1-2 g |
Tips for the Best Results
Cut rhubarb evenly. Uniform pieces ensure even cooking. Aim for ½-inch chunks so they soften perfectly without turning mushy.
Don’t skip the butter. It’s what transforms the dry cake mix into a crispy, golden topping. Make sure to drizzle it evenly across the entire surface.
Let it bubble. You want to see the rhubarb juices bubbling up through the cake layer. This means the fruit is perfectly cooked and the flavors have melded together.
Serving Suggestions
Rhubarb dump cake is best served warm, straight from the oven. The contrast of hot cake and cold ice cream is absolutely divine.
Top each serving with a scoop of vanilla ice cream, whipped cream, or even Greek yogurt for breakfast. The creamy element balances the tartness beautifully.
For extra flair, dust with powdered sugar or add a drizzle of caramel sauce. Fresh mint leaves make a pretty garnish for special occasions.
Storage and Make-Ahead Tips
Store leftover rhubarb dump cake covered in the refrigerator for up to 4 days. The flavors deepen overnight, making day-two servings even more delicious.
Reheat individual portions in the microwave for 30-40 seconds, or warm the entire pan in a 300°F oven. You can also enjoy it cold, though the texture is best when warmed.
To make ahead, assemble the cake up to the point of baking, cover tightly, and refrigerate for up to 24 hours. Bake as directed when ready to serve.
Variations to Try
Strawberry rhubarb dump cake: Replace half the rhubarb with sliced strawberries for a sweeter, more balanced flavor. This combo is a classic for good reason.
Spiced rhubarb version: Add ½ teaspoon cinnamon and ¼ teaspoon nutmeg to the cake mix before sprinkling. The warm spices complement the tartness beautifully.
Gluten-free option: Use a gluten-free cake mix and ensure all other ingredients are certified gluten-free. The texture remains just as delicious.
Frequently Asked Questions
Can I use frozen rhubarb for dump cake?
Yes! Frozen rhubarb works perfectly in this recipe. There’s no need to thaw it first—just use it straight from the freezer. The baking time might need an extra 5 minutes, and you may get a slightly saucier base, which many people prefer.
Why is my rhubarb dump cake soggy?
Sogginess usually happens when the butter isn’t distributed evenly or when there’s too much fruit moisture. Make sure to drizzle butter across the entire surface of the cake mix. If using very juicy rhubarb, reduce the sugar slightly or add 2 tablespoons of cornstarch to the fruit layer.
Can I make rhubarb dump cake ahead of time?
You can assemble it up to 24 hours ahead—layer everything except the butter, cover tightly, and refrigerate. Add the melted butter right before baking. For fully baked cake, store covered in the fridge for up to 4 days and reheat before serving.
