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Magic Rhubarb Dump Cake

Be sure to share this simple dump and go "no sugar added" rhubarb dump cake with everyone who has rhubarb in the garden! It's a great way to use it up whether it's fresh or frozen.
Pan with rhubarb cake in it with a spoonful taken out of the cake.

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There is nothing easier than a dump cake! The clue is right in the name, dump it and bake it, no mixing needed. And this one is made using fresh or frozen rhubarb for a rhubarb dump cake that is FULL of flavor!

Rhubarb Dump Cake in pan with two plates of cake and a scoop of ice cream.

Layers of rhubarb, strawberry jello, yellow cake mix, melted butter, and water bake together with no mixing to make this rhubarb dump cake a truly simple cake. Sweet and crispy on top, tangy rhubarb underneath!

A spoon in a pan of rhubarb dump cake.

Making a cake like this is one of the perfect storm sorts of ideas, you have extra rhubarb, you find a cake mix in the cupboard and a box of jello and suddenly you’re making a cake.

Pan with rhubarb cake in it with a spoonful taken out of the cake.

Why are there dry spots on this cake?

One of the hallmarks of this cake is that you don’t mix it. You simply layer it. Therefore you will have some spots of drier cake mix. They may LOOK completely dry but then underneath they’re touching the juicy part of the cake.

Can I eat raw cake mix? Don’t they tell you not to eat raw flour? The cake mix isn’t raw once you’ve baked it. There’s nothing to make you sick because it’s all been baked.

There are parts with crumbly dry bits though.

View of a dump cake with dry crumbly parts, rhubarb juice, and moist cake pieces too.

Why don’t you add sugar to this Dump Cake Recipe?

This is a “No Added Sugar Dump Cake Recipe.” There are plenty of recipes out there that call for added sugar. But I have to tell you that they’re too sweet for me! And I love sweets.

The Jello and the cake mix are full of sugar and they make this recipe sweet enough.


BUT if you don’t think you’re going to like it with tangy rhubarb on the bottom and sweet crispy cake on the top you can always add up to a cup of sugar AFTER the Jello and BEFORE the cake mix. Don’t stir it in, this cake is about layering, no mixing!

Ingredients for a dump cake in the pan you bake it in.

What do I need to make this Rhubarb Dump Cake?

  • Chopped Rhubarb
  • Small Box of Jello, can be ANY flavor
  • ***OPTIONAL*** 1/2-1 cup sugar, you don’t need it but then rhubarb is tangy so add as desired!
  • Yellow or White Cake Mix
  • Melted butter
  • Water
  • 9×13 pan

Do I thaw the Rhubarb Before adding it to the pan?

I do not thaw rhubarb before adding it to MOST recipes. It gets VERY soupy when it thaws out so it’s best used as close to frozen as possible. For this cake, I let it thaw for about 20 minutes or until I could break it apart with my hands BUT before it was soft and mushy.

A single perfect bite of Rhubarb Dump Cake.

Other Amazing Rhubarb Recipes

Pan with rhubarb cake in it with a spoonful taken out of the cake.

Rhubarb Dump Cake

4.91 from 85 votes
Be sure to share this simple dump and go "no sugar added" rhubarb dump cake with everyone who has rhubarb in the garden! It's a great way to use it up whether it's fresh or frozen.
Course: Dessert Recipes
Cuisine: American
Prep Time: 10 minutes
Cook Time: 1 hour
Total Time: 1 hour 10 minutes
Servings: 10 servings
Calories: 325kcal
Author: Laura
Print Recipe


  • 4 cups chopped rhubarb fresh or frozen, if using frozen do not thaw!
  • one 3 ounce box of Strawberry Jello or use ANY flavor you like
  • ***OPTIONAL*** 1/2 cup sugar see notes for more info!
  • one 16 ounce box yellow OR white cake mix I used a Duncan Hines yellow cake
  • 1/2 cup butter melted
  • 1 cup water


  • preheat the oven to 350°
  • layer the rhubarb in the bottom of a 9×13 pan, if it's frozen do not thaw it, just let it thaw enough to break apart
  • sprinkle the Jello over the top
  • sprinkle the dry cake mix over the Jello
  • pour the melted butter on top of the cake mix
  • and drizzle the water over the top of everything
  • bake in the preheated oven 55-60 minutes or until the top is set in places and the fruit is bubbling hot
  • cool a little before serving, this doesn't cut like a cake so be ready to scoop it up!


This is a No Sugar Added Recipe, if you WANT it sweeter add up to a cup of sugar to the layers between the Jello and the Cake mix, don't stir it in, just sprinkle it over
With JUST the jello the tangy rhubarb comes through, with sugar it is sweeter!


Serving: 1g | Calories: 325kcal | Carbohydrates: 43g | Protein: 3g | Fat: 16g | Saturated Fat: 8g | Polyunsaturated Fat: 8g | Cholesterol: 30mg | Sodium: 250mg | Fiber: 1g | Sugar: 31g

Magic rhubarb dump cake.
laura sampson

About Laura

Laura is on a mission to teach modern family oriented women how to make old-fashioned foods new again. A wife and mom of 3 boys, Laura understands the struggles of trying to serve a home-cooked meal each night. She provides recipes and cooking hacks for busy moms to create dishes they may think take more time or skill than they have to make. Read more...

5 thoughts on “Magic Rhubarb Dump Cake”

  1. This was delicious without the extra sugar…the flavor of the rhubarb comes through! Will definitely make this again.

  2. Hi, Laura–I plan to make this Rhubarb Dump Cake for our upcoming Fourth of July gathering, and I am not much of a baker. I would like to ask, please: for my friends who aren’t as accustomed to rhubarb, would it be possible to turn this into a Strawberry-Rhubarb Dump Cake?? If so, what changes need to be made to this wonderful recipe, which I’m very much looking forward to trying?? Especially any changes in ingredients or their amounts in this recipe, resulting from the addition of frozen strawberries (or I could use fresh strawberries, but I will definitely have to use frozen rhubarb)….!!

    I can only imagine how busy you must be, but if you could possibly write back before July 1, I would be grateful. I am older, don’t drive, and will need suffficient time to assemble everything I need so as to make this Dump Cake in time for my gathering….!! 🙂

    Many thanks, Laura, and kindest regards,

    Anne B.

  3. 5 stars
    My favorite way to make rhubarb now! I make it in crockpot – a couple of tweaks, I just mix in the frozen berries with the rhubarb( Ive had sitting around for two weeks till almost dried out), I add the jello, a tablespoon or two of cornstarch, 1/3 cup sugar and the water and mix it all together , pop it into the greased crockpot, sprinkle on the cake mix and top with sliced butter, instead of melted and cook it on high with a paper towel under the lid to absorb the moisture and presto in 3 hours – its done. The cobbler/ dump cake is too yummy – I like it best cold, with a splash of heavy cream over it – so, so good. Thank u for the delicious recipe

  4. 5 stars
    Made this awesome dessert and it was a hit!! I used 1/3 c sugar and just less than 1 c water as the rhubarb had juice… will definitely make again. Hubby approved


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