Every summer, without fail, my kitchen smells like something magical is happening in the oven. Tangy fruit, buttery cake topping, and that warm caramel-y sweetness that makes the whole family wander in asking, "What are you making?" That smell? That's rhubarb dump cake — and it's been a part of my family recipe collection for as long as I can remember.
I first had this recipe at a family gathering when I was maybe ten years old. My Aunt Kaye pulled this bubbling, golden cake out of the oven and set it on the counter, and I couldn't believe something that looked that impressive only took about ten minutes to put together. No mixing bowls, no electric mixer, no complicated steps.
If you love easy summer desserts, you'll also want to check out my Bourbon Pecan Peach Crisp — it's that same "minimal effort, maximum reward" kind of baking that I'm honestly obsessed with.
Jump to:
- Why You'll Love This Easy Rhubarb Dump Cake Recipe
- Ingredients For This Rhubarb Dump Cake
- How To Make Rhubarb Dump Cake Step By Step
- Storage And Reheating Tips
- Rhubarb Dump Cake Variations And Tips
- Frequently Asked Questions About Rhubarb Dump Cake
- Recipes You May Like
- Make This Rhubarb Dump Cake This Weekend
- Aunt Kaye's Rhubarb Dump Cake
Why You'll Love This Easy Rhubarb Dump Cake Recipe
- Takes just 10 minutes of prep — seriously, anyone can do this
- Uses a box of cake mix, so no measuring flour or leavening agents
- Works beautifully with fresh or frozen rhubarb
- The strawberry gelatin adds color and a gorgeous sweet-tart flavor
- Perfect for potlucks, summer cookouts, or a random Tuesday night dessert
- Totally customizable with different fruit and gelatin combinations
Ingredients For This Rhubarb Dump Cake
- 4 cups fresh rhubarb, chopped (or frozen, thawed and drained)
- 1 cup granulated sugar
- 1 (3 oz) package strawberry-flavored gelatin (like Jell-O)
- 1 (15.25 oz) box yellow cake mix (dry, straight from the box)
- 1 cup water
- ¼ cup unsalted butter, thinly sliced
Substitution note: You can swap the strawberry gelatin for raspberry, cherry, or even peach — Aunt Kaye tried them all. The yellow cake mix can also be swapped for white cake mix if that's what you have on hand.
How To Make Rhubarb Dump Cake Step By Step
This is genuinely one of the easiest desserts I've ever made — and I went to cooking school! The beauty of a dump cake recipe is right there in the name.
Prep Your Pan And Oven
- Preheat your oven to 375°F (190°C).
- Lightly grease a 9x13-inch baking dish with butter or non-stick spray.
Layer The Rhubarb Dump Cake
- Spread the chopped rhubarb evenly across the bottom of the baking dish.
- Sprinkle the 1 cup of sugar evenly over the rhubarb — don't stir.
- Sprinkle the dry strawberry gelatin evenly over the sugar layer.
- Pour the dry cake mix evenly over the top — do NOT mix it in.
- Slowly pour 1 cup of water over the entire cake mix layer.
- Lay the butter slices evenly across the top, covering as much surface area as possible. This step is key — no dry spots!
Bake Until Golden
- Bake uncovered for 45 minutes, or until the top is golden brown and the rhubarb is bubbling up around the edges.
- Let it cool for at least 10-15 minutes before serving — the filling thickens up beautifully as it cools.
Serve it warm with a scoop of vanilla ice cream or a dollop of whipped cream. Bradley ate three servings the first time I made this and tried to claim he "didn't even like rhubarb."
Storage And Reheating Tips
- Refrigerator: Cover the baking dish tightly with plastic wrap or foil and store for up to 4 days.
- Freezer: Portion into individual servings, wrap well, and freeze for up to 2 months.
- Reheating: Warm individual portions in the microwave for 60-90 seconds. You can also reheat the whole dish in a 325°F oven for about 15 minutes, loosely covered with foil.
The flavor actually gets a little better on day two once all those fruit juices settle into the cake topping.
Rhubarb Dump Cake Variations And Tips
Want to make this your own? Here's what I've tried (and what the family has approved):
- Strawberry Rhubarb Dump Cake: Add 1 cup of fresh or frozen strawberries along with the rhubarb. Use strawberry gelatin. This is the most popular version in our house.
- Peach Rhubarb Dump Cake: Swap half the rhubarb for sliced peaches and use peach gelatin. It tastes like summer in a pan.
- Mixed Berry Dump Cake: Use 4 cups of mixed berries in place of rhubarb with raspberry or berry gelatin. Amy calls this her "purple cake."
- Spice it up: Add ½ teaspoon of cinnamon to the sugar layer before adding the gelatin. It adds a warm, cozy depth.
Here's the thing — have you ever pulled a dump cake out of the oven and the topping still looked dry and powdery in spots? That's a butter distribution problem. Make sure every inch of dry cake mix is covered by a thin slice of butter before it goes into the oven. I learned this the hard way at a church potluck — nobody needs a chalky dump cake situation.
Frequently Asked Questions About Rhubarb Dump Cake
Can I Use Frozen Rhubarb Instead Of Fresh?
Yes, absolutely! Frozen rhubarb works just as well in this recipe. The key is to thaw it completely and drain off as much excess liquid as possible before adding it to the pan.
Extra moisture from frozen fruit can make the cake layer soggy and prevent it from crisping up on top. I usually spread it on a clean kitchen towel for a few minutes to absorb any extra liquid.
Can I Substitute The Rhubarb With Other Fruits?
Definitely — this is one of those recipes that's made for experimenting. Strawberries, peaches, mixed berries, or even canned cherries (drained) all work beautifully.
Aunt Kaye never made the same version twice, honestly. She'd match her fruit to whatever flavored gelatin she had in the pantry, and it always turned out delicious.
How Do I Store Leftover Rhubarb Dump Cake?
Cover it tightly and refrigerate for up to 4 days. For longer storage, freeze individual portions wrapped in plastic and sealed in a freezer bag for up to 2 months.
Reheat straight from the fridge in the microwave in about 90 seconds — it warms up perfectly and the edges get a little chewy in the best way.
Why Is My Dump Cake Topping Still Powdery After Baking?
This is the most common dump cake problem, and it has one fix: butter coverage. Every bit of dry cake mix needs to be covered by a butter slice before it goes into the oven.
If you've already baked it and the topping came out dry in spots, you can add a few more small pats of butter on top and return it to the oven for another 5-10 minutes.
Recipes You May Like
- Pumpkin Brownies — Another crowd-pleasing baked dessert that's just as easy and satisfying as this dump cake.
- Moist Banana Chocolate Chip Muffins — If you love easy fruit-based baking, these muffins are on constant rotation in my kitchen.
- Chocolate Molten Lava Cakes — For when you want something a little more indulgent but still totally doable on a weeknight.
Make This Rhubarb Dump Cake This Weekend
This recipe has been in my family for decades, and there's a reason it keeps coming back every summer. It's simple, it smells incredible while it bakes, and it makes a whole 9x13 pan that feeds everyone.
John still asks for this by name every June when the rhubarb shows up at the farmers' market. And now that Amy helps me layer the ingredients, she's convinced it's "her recipe."
Give this a try this week and let me know what variations you use — I'd love to hear how your family makes it their own! And don't forget to save this to Pinterest so it's ready for you all summer long.
Aunt Kaye's Rhubarb Dump Cake
- Total Time: 55 minutes
- Yield: 12 portions 1x
Description
An easy, irresistible rhubarb dump cake — tangy, golden, and bubbling with sweet-tart flavor, ready with just 10 minutes of prep. This is Aunt Kaye's legendary summer dessert that brings the whole family wandering into the kitchen.
Ingredients
- 4 cups fresh rhubarb, chopped (or frozen, thawed and drained)
- 1 cup granulated sugar
- 1 (3 oz) package strawberry-flavored gelatin (like Jell-O)
- 1 (15.25 oz) box yellow cake mix (dry, straight from the box)
- 1 cup water
- ¼ cup unsalted butter, thinly sliced
Instructions
- Preheat your oven to 375°F (190°C).
- Lightly grease a 9x13-inch baking dish with butter or non-stick spray.
- Spread the chopped rhubarb evenly across the bottom of the baking dish.
- Sprinkle the 1 cup of sugar evenly over the rhubarb — do not stir.
- Sprinkle the dry strawberry gelatin evenly over the sugar layer.
- Pour the dry cake mix evenly over the top — do NOT mix it in.
- Slowly pour 1 cup of water over the entire cake mix layer.
- Lay the butter slices evenly across the top, covering as much surface area as possible.
- Bake uncovered for 45 minutes, or until the top is golden brown and the rhubarb is bubbling up around the edges.
- Let it cool for at least 10-15 minutes before serving — the filling thickens up beautifully as it cools.
- Serve warm with a scoop of vanilla ice cream or a dollop of whipped cream.
Notes
Make sure every inch of dry cake mix is covered by a thin slice of butter before baking — this is the key to a perfectly golden top with no dry, powdery spots. If using frozen rhubarb, thaw completely and drain excess liquid before adding to the pan. The flavor actually gets a little better on day two once all those fruit juices settle into the cake topping.
- Prep Time: 10 minutes
- Cook Time: 45 minutes
- Category: Dessert
- Method: Baked
- Cuisine: American
