This easy Rhubarb Dump Cake is one of the simplest spring desserts to prepare. With just a few pantry staples and fresh or frozen rhubarb, this cozy cake-cobbler hybrid comes together in minutes. The sweet-tart fruit filling bubbles up beneath a buttery cake mix topping, creating a nostalgic dessert that’s ideal for potlucks, family meals, or using up abundant seasonal rhubarb.
I make this recipe every rhubarb season because it requires almost no prep and always gets great feedback. Serve it warm with vanilla ice cream or let it cool and enjoy it chilled—the texture and flavor are delightful either way.
If you enjoy rhubarb recipes, try other ideas like healthy orange-rhubarb muffins, frosted rhubarb cookies with cream cheese frosting, strawberry-rhubarb lemonade, or homemade rhubarb fruit leather.
Why You Will Love Rhubarb Dump Cake
A simple box of cake mix becomes a crisp, buttery topping with just a little butter placed over the dry mix—no beating or elaborate technique needed. This recipe is forgiving and quick while delivering a crowd-pleasing balance of sweet and tart.
- Minimal ingredients and simple steps
- No mixing bowls required—assemble in the baking pan
- Delicious sweet-and-tart flavor profile
- Perfect for spring and early summer gatherings
- Make-ahead friendly for entertaining
- Works equally well with fresh or frozen rhubarb
Ingredients Needed for Rhubarb Dump Cake
- Chopped rhubarb – 4 to 5 cups. If you don’t have rhubarb, other fruits like cherries or apples can be substituted.
- Sugar – ½ cup granulated sugar; increase slightly if your rhubarb is very tart.
- Yellow cake mix – one standard box. Use a different flavor (vanilla, butter, spice) for variation if desired.
- Butter, cold and cubed – 2 sticks. Unsalted butter is recommended so you can control sodium; or use pats of butter if you prefer not to cube and melt it.
- See the recipe card area for exact measurements and notes.
How to Make Rhubarb Dump Cake
Step 1: Preheat the oven to 350°F. Grease a 9 x 13 (or 9 x 9 for a smaller batch) glass or metal baking pan. Scatter the chopped rhubarb evenly in the pan and sprinkle the sugar over the fruit.
Step 2: Evenly sprinkle the dry cake mix over the rhubarb and sugar so the fruit layer is completely covered.
Step 3: Cut the cold butter into tablespoon-sized cubes and distribute them evenly over the dry cake mix so the topping will melt and form a golden crust while baking.
Step 4: Bake at 350°F for 40 to 60 minutes, checking at 40 minutes. The top should be golden and crispy and the fruit should be bubbling. If needed, bake an additional 10–20 minutes until done. Let the pan rest briefly before serving to allow the filling to set.
Variations to Try
- Strawberry-Rhubarb – Replace a portion of rhubarb with sliced strawberries for a sweeter, colorful version.
- No-Gelatin Filling – Skip any gelatin or Jell-O and add vanilla or cinnamon to enhance the fruit’s natural flavor.
- From-Scratch Topping – Use a simple homemade cake mix (flour, sugar, baking powder) for a pantry-friendly, scratch version.
- Different Cake Mix Flavors – Try spice, butter, or vanilla cake mix for new flavor profiles.
- Frozen Rhubarb – Use frozen rhubarb straight from the freezer; you may need to add a few extra minutes of baking time.
Rhubarb Dump Cake Expert Tips
- Do not mix the layers—keeping them in layers allows the topping to crisp properly.
- Cut rhubarb into uniform small pieces so it cooks evenly.
- Let the cake cool slightly or chill before slicing for cleaner portions.
- Add a few extra butter cubes if you prefer an especially crispy, browned topping.
- Taste your rhubarb; very tart stalks may require a bit more sugar to balance the acidity.
Serving Suggestions
- Serve warm with vanilla ice cream or a scoop of whipped cream for a classic pairing.
- Top with fresh whipped cream, custard, or a drizzle of heavy cream.
- Bring to BBQs, potlucks, or family gatherings—easy to transport and serve.
- Ideal for spring celebrations like Mother’s Day and Easter.
- A delicious way to use homegrown garden rhubarb.
Recipe FAQs
Yes. Frozen rhubarb works well and does not need to be thawed first; just account for a little extra bake time if the pan is cold from the frozen fruit.
Store in an airtight container in the refrigerator for up to three days. Reheat individual portions briefly for a warm serving.
A powdery top usually means the butter or other liquid did not get distributed evenly. Ensure butter cubes are spread across the surface so the cake mix can dissolve and brown properly.
Right out of the oven the cake can be a bit gooey because of melted butter and warm fruit. Allow it to cool for a short time so the filling sets and slices more cleanly.
Other Recipes To Try
Jersey Mikes Chicken Salad Recipe-
Air Fryer Recipes for Beginners
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Air Fryer Cookie Dough
-
Crock Pot Swamp Potatoes
If you try this Rhubarb Dump Cake or any other recipe from this collection, please leave a star rating and share your experience in the comments. Feedback helps refine recipes and inspires new variations.
Rhubarb Dump Cake
5 from 3 reviews
Description
This Rhubarb Dump Cake is effortless—no mixing required. Layer the ingredients in the pan and let the oven turn them into a crisp-topped, bubbling fruit dessert.
Ingredients
- 4–5 cups chopped rhubarb
- ½ cup granulated sugar
- 1 box yellow cake mix
- 2 sticks butter, cold and cut into cubes
Instructions
- Preheat oven to 350°F. Grease a 9 x 13 (or 9 x 9) baking pan.
- Spread chopped rhubarb in the pan and sprinkle with sugar.
- Evenly cover the fruit with the dry cake mix.
- Scatter cold butter cubes across the cake mix so the surface is well covered.
- Bake for 40–60 minutes, checking at 40 minutes. The top should be golden and the filling bubbling. Cool briefly before serving.
Notes
Allow the cake to rest after baking so the filling sets; serving immediately can result in a slightly gooey texture. Adjust sugar to taste if your rhubarb is especially tart.
Nutrition
- Calories: 208
- Sugar: 20 g
- Fat: 9 g
- Saturated Fat: 3 g
- Carbohydrates: 33 g
- Fiber: 1 g
- Protein: 1 g
Recipe adapted from Our Fun with Five