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With only 5 ingredients and 10 minutes or less of prep, my Rhubarb Dump Cake recipe is an easy dessert even beginners will love to make! No baking experience required.
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I am so excited to share this rhubarb dump cake recipe with you. It is one of the easiest desserts you can make, even if you're new to baking!
With just five simple ingredients - rhubarb, sugar, boxed cake mix, water, and butter - this rhubarb cake comes together in about 10 minutes and bakes in an hour. No mixing, and even better: just one dish to clean!
Rhubarb dump cake is a perfectly balanced dessert with tart rhubarb, sweet yellow cake, and a buttery topping that's slightly crisp on top and soft underneath. It's so good, you'll forget how simple it was to prepare.
Serve it warm with whipped cream or a scoop of vanilla ice cream. Once you try it, I guarantee you'll want to keep it in your regular rotation!
Ingredients for Rhubarb Cake with Cake Mix
| Ingredient | Notes & Substitutions |
|---|---|
| Rhubarb | I'm using fresh rhubarb in this recipe, but you could also use frozen rhubarb you've thawed. Canned rhubarb is a possibility too, but it tends to come in syrup that may over-sweeten the dish. |
| Sugar | Plain white granulated sugar works best for this dump cake recipe! |
| Yellow Cake Mix | I'm just using boxed yellow cake mix, but you can also use homemade cake mix if you prefer. |
| Water | This helps combine the ingredients and hydrate the cake mix. |
| Butter | Use unsalted butter in this recipe! I like to use a high-quality butter, but any butter will do as long as it's unsalted. |
Using Fresh Rhubarb? Here's How to Cut It
- Wash the rhubarb in cool running water and dry it with paper towels.
- Cut off the leaves, then trim the end of the root. Discard both the root and leaves. They are not edible.
- On one end, at the end of the stalk, cut into the rhubarb. Grab hold of where you cut and pull down. This will peel off a layer of stringy fibers you can discard.
- Slice the stalk into square chunks.
How to Make Rhubarb Dump Cake
Step 1: Prep the Baking Dish
Preheat the oven to 350°F. Grease a 9 by 13-inch baking dish with cooking spray or butter. Add 4 cups sliced rhubarb to the dish and spread to cover the bottom completely.
Step 2: Add Sugar
Pour in 1 cup granulated sugar.
Step 3: Add Cake Mix
Spread 1 box moist yellow cake mix over the top of the rhubarb sugar mixture.
Step 4: Add Water
Evenly pour in 1 cup of water.
Step 5: Add Butter
Pour in melted unsalted butter. Making sure to evenly pour it over the cake.
Step 6: Bake and Enjoy!
Place the baking dish in the oven and bake for 45 minutes to 1 hour, or until the top is browned and a toothpick comes out clean from the center.
Top Reviews
Love this recipe. Have made it twice. Second time I used a strawberry cake mix. It was the best. - Marcie
Enjoyed this with family for our Sunday Supper! I think I’ll try reducing the sugar next time, but I’ll definitely make it again. It was extra special still a little warm and with vanilla ice cream. 😋 - Marta
This was absolutely delicious. Thanks for sharing. - Diane
See them all here→ or keep scrolling to the comments section below! I appreciate all of the amazing reviews on this recipe.
Isabel's Top Tips for Making Rhubarb Dump Cake
- If you're unable to find fresh rhubarb, you can use frozen. Be sure to fully thaw before using.
- This dump cake is very moist - check the center with a knife to tell when it's fully baked through. You want the knife to come out clean.
- Evenly pour the butter over the other ingredients in the baking dish. You want that melted butter to cover every bit of the top. It will give you the most beautifully browned and flavorful dump cake recipe ever!
- If you are slicing your own rhubarb, make sure to discard the roots and leaves. The roots and leaves are not safe to eat.
FAQ
Hothouse rhubarb, which refers to rhubarb grown in a heated greenhouse rather than in the field, is at its peak at the beginning of the year through early summer. It actually tends to taste different than field-grown rhubarb, having a more mild flavor.
Field-grown rhubarb is in season from early spring to mid-summer.
You can also buy it frozen year-round, which means you can make this dump cake recipe whenever you like!
Absolutely. Experiment with other fruits and see what you enjoy best! Blueberries, blackberries, raspberries, peeled apples - anything you enjoy in a pie, you'll love in a dump cake. Scroll below for more of my dump cake recipes.
Strawberry is a classic pairing with rhubarb, but any sweet berry will complement it beautifully in rhubarb dump cake. You can also try using other sweet fruits, like pears, apples, or peaches.
As long as you distribute your ingredients evenly, this generally shouldn't happen. But, if you want to play it safe, you can mix the butter, cake mix, and water ahead of time before pouring it over the other ingredients.
Absolutely. I've only tried this with yellow cake mix, but you could also try white cake mix, lemon cake mix, strawberry cake mix, or even chocolate cake mix. You can also make homemade cake mix and use that.
What to Serve with Rhubarb Dump Cake
Dump Cake Recipes
Amazing Rhubarb Dump Cake
Video
Equipment
- 9 by 13 inch baking dish
Ingredients
- 4 cups sliced rhubarb
- 1 cup granulated sugar
- 1 box moist yellow cake mix
- 1 cup cold water
- ¾ cup unsalted butter - melted
Instructions
- Preheat oven to 350°F. Grease a 9 by 13-inch baking dish. Add the sliced rhubarb to the baking dish and spread to cover the bottom of the dish.4 cups sliced rhubarb
- Pour the granulated sugar over the top of the sliced rhubarb.1 cup granulated sugar
- Next, spread the box yellow cake mix over the top of the rhubarb and sugar.1 box moist yellow cake mix
- Pour the water over the cake mix.1 cup cold water
- Then, evenly pour the melted butter over the cake mix.¾ cup unsalted butter
- Place in the oven and bake for 45-60 minutes or until the top is browned and a knife comes out clean from the center.
Notes
- If you're unable to find fresh rhubarb, you can use frozen rhubarb. Be sure to fully thaw before using.
- This dump cake is very moist - be sure to fully bake and check the center with a knife. You want the knife to come out clean.
- Make sure to evenly pour the butter over the other ingredients in the baking dish. You want that melted butter to cover every bit of the top. It will give you the most beautifully browned and flavorful dump cake recipe ever!
- If you are slicing your own rhubarb, make sure to discard the roots and leaves. The roots and leaves of rhubarb are not safe to eat.
Lydia says
I love dump cakes! I'm curious though why this one calls for water and butter to be poured over the cake mix when typically it's just butter. Is there a reason for the water? I just made this and the topping was very cake like- not the usual delightfully crunchy topping that my crunch cakes have always had.
Em Beitel says
Hi Lydia! This is really up to preference - you could leave the water out if you'd like a crunchier topping. Thank you for your question!
Jill says
Everyone liked it but i used half the sugar and twice the rhubarb. I will use less water next time.
Em Beitel says
That's a great adjustment, Jill! Thank you for sharing!
Carol Scudder says
Can I use home made rhubarb jam for this recipe
Em Beitel says
Hi Carol! I haven't used jam to make a dump cake before, so I'm not certain how it would turn out and am concerned the texture might not quite work after baking. My recommendation would be to test it with a smaller dump cake first if you'd like, or to simply mix the jam with the fresh sliced rhubarb for texture, and use less sugar depending on the sweetness of your jam.
Diane says
This was absolutely delicious. Thanks for sharing.
Isabel Laessig says
Diane, I am so happy to hear you enjoyed it! Thank you for your comment!
Marta says
Enjoyed this with family for our Sunday Supper! I think I’ll try reducing the sugar next time, but I’ll definitely make it again. It was extra special still a little warm and with vanilla ice cream. 😋
Isabel Laessig says
This is wonderful to hear, Marta! I am so glad you enjoyed it together!
Marcie says
Love this recipe. Have made it twice. Second time I used a strawberry cake mix. It was the best.
Isabel Laessig says
That sounds wonderful, Marcie. I'm so glad you enjoyed it!
Donna says
I use a sugar free cake mix, and less than 1/2 cup of sugar, and it is absolutely delicious, and loved by all! Thank you!!
Isabel Laessig says
So glad you enjoyed it - thank you, Donna!