Rhubarb Dump Cake without jello is the one-pan dessert made with fresh or frozen rhubarb, yellow cake mix, melted butter, and a warm sprinkle of cinnamon and nutmeg. No mixing, no fuss; just layer, bake, and dig in. I like to top it with a scoop of vanilla ice cream or a dollop of freshly whipped cream, and you've got a crowd-pleasing dessert that comes together in minutes.
- A great way to use up extra frozen rhubarb you have stored in the freezer.
- Made in one pan so minimal dishes to wash!
- Crunchy, sweet cobbler-like topping over sweetened rhubarb is a delicious dessert.
- An easy recipe to get your kids to eat rhubarb.
Ingredients needed to make rhubarb dump cake:
Just seven simple pantry and produce items stand between you and this warm, bubbly dessert.
Recipe Card?
To find the full printable recipe with specific measurements and directions CLICK HERE to go to the recipe card.
Ingredient Substitutions
Don't stress if you're missing something or want to put your own spin on things - this recipe is wonderfully flexible.
| Ingredient | Substitution |
|---|---|
| Yellow cake mix | White cake mix, vanilla cake mix, lemon cake mix, or spice cake mix. |
| Granulated sugar | Splenda or other granulated sugar substitute. |
| Salted butter | Unsalted butter (add a pinch of salt to the cake mix layer) |
| Rhubarb only | Add 1-2 cups of frozen or fresh strawberries, raspberries, or blueberries alongside the rhubarb. |
| Cinnamon & nutmeg | Pumpkin pie spice or cardamom for a different warm-spice profile. |
Can I use strawberries with this rhubarb dump cake?
Absolutely! Strawberry rhubarb dump cake is a classic combo. Simply replace half the rhubarb with fresh or frozen strawberries - no other adjustments needed.
Step-by-Step Instructions
The beauty of a dump cake is that it's almost impossible to mess up - IF you follow one golden rule: do not stir!
Here's exactly how to do it right.
Prep Your Pan
Preheat your oven to 350°F. Spray a 9x13-inch baking pan generously with non-stick cooking spray. Glass or ceramic pans work great here and let you see when the bottom is bubbling.
Layer the Rhubarb
Spread your chopped rhubarb in an even layer across the bottom of the prepared pan. If using frozen rhubarb, no need to thaw it ...just use it straight from the freezer. Cut pieces small (roughly ½-inch) to prevent soggy pockets as the rhubarb releases its moisture during baking.
Add the Spices
Sprinkle the cinnamon and nutmeg evenly over the rhubarb. These spices are optional, but they add a cozy, bakery-worthy aroma and flavor you won't want to skip.
Cover with Sugar
Sprinkle the granulated sugar evenly over the rhubarb and spice layer. The sugar will dissolve into the rhubarb as it bakes, creating a sweet, jammy fruit base underneath the topping.
Add the Cake Mix - Don't Press It!
Sprinkle the dry cake mix directly from the box over the sugared rhubarb in an even layer. Do not press it down or stir. Pressing the mix can compact it into a dense crust that won't hydrate properly, leaving you with chalky, dry patches on top.
Sprinkle the Water
Evenly sprinkle the water over the dry cake mix. This starts the hydration process and helps the topping bake into that signature golden, crunchy crust.
Drizzle the Butter
Drizzle the melted butter over the entire surface, focusing on any dry-looking spots of cake mix. Butter is what creates those beautiful golden, crispy patches on top; don't skip corners!
Bake, Covered Then Uncovered
Cover the pan tightly with aluminum foil and bake for 45 minutes. Remove the foil and bake an additional 15 minutes, or until the top is golden brown and the rhubarb is bubbling up around the edges. That bubbling is your sign the filling is fully cooked.
Serve Warm
Remove from the oven and let it rest for 5-10 minutes. Serve warm with vanilla ice cream or freshly whipped cream.
Seasonal Favorite
This is the best homemade seedless black raspberry jam recipe made with fresh or frozen black raspberries.
Make-Ahead Tips
Life gets busy - and yes, this cake can absolutely work ahead of schedule. A little planning goes a long way here.
- Assemble the entire cake the night before, cover it tightly with foil, and refrigerate it unbaked.
- Pull it from the fridge while you preheat the oven, and bake as directed - you may need to add 5-10 extra minutes since the pan will be cold.
- Alternatively, bake the cake fully, cool it completely, cover tightly, and refrigerate for up to 3-4 days.
- Reheat individual portions in the microwave in 30-second increments, or warm the whole pan in a 300°F oven for 15-20 minutes until heated through.
Storage Tips
Rhubarb dump cake stores like a champ - so don't be afraid to make a full pan even for a smaller crowd.
- Refrigerator: Cool completely, then cover tightly with plastic wrap or foil. Stores well for 3-4 days.
- Freezer: Cut into individual portions, wrap each tightly in plastic wrap then a layer of foil, and place in a freezer-safe zip-lock bag. Label with the date and freeze for up to 3 months. Thaw overnight in the refrigerator before reheating.
- Reheating: Microwave individual portions on high in 30-second intervals, watching for hot spots. To crisp the topping back up, pop it in a 325°F oven for 10 minutes uncovered.
- Food safety reminder: Never leave this cake at room temperature for more than 2 hours.
Frequently asked questions, answers and tips:
Once the cake has been cooled, store it in the refrigerator covered with plastic wrap or foil.
Scoop a portion into a microwave-safe bowl and microwave in 30-second intervals, checking for hot spots between each. To bring back some of that crispy topping, pop it in a 325°F oven for 10 minutes uncovered.
Sprinkle the cake mix over the sugared rhubarb and do not press it down. By pressing it you can form a crust and not allow the cake mix to fully hydrate leaving dry cake mix on the surface.
Please keep in mind that freezing may affect the texture of the rhubarb dump cake slightly, but it should still be delicious!
Let the cake cool completely before freezing. Cut it into individual portions or leave it whole if you prefer. Wrap each portion tightly with plastic wrap and then with aluminum foil to prevent freezer burn.
Label each packet with the date and contents, so you know what it is and when you made it. Place the wrapped portions in a single layer in an airtight container or freezer-safe ziplock bag. Freeze for up to 3 months.
When ready to serve again, take out the frozen packets from the freezer and let them thaw in the refrigerator overnight or at room temperature for a few hours before reheating as desired.
Rhubarb is 95% water, and when it releases liquid during baking it can make the filling gummy. Fix: Cut rhubarb into small, uniform pieces and resist the urge to add extra liquid.
Frozen rhubarb releases more moisture than fresh. Fix: Use it straight from frozen (don't thaw), and consider extending the uncovered bake time by 5-10 minutes to allow extra moisture to evaporate.
Usually caused by covering with foil the whole time or using a dark pan that traps steam. Remove foil for the last 15 minutes and check for golden color.
More Rhubarb Recipes To Explore
Ingredients
- 4 Cups (488 g) Rhubarb chopped
- 1 Teaspoon (1 Teaspoon) Cinnamon
- ¼ Teaspoon (¼ Teaspoon) Nutmeg
- 1 box (1 box) Cake mix
- 1 Cup (200 g) Sugar
- 1 Cup (236 ⅗ ml) Water
- ½ Cup (113 ½ g) Butter melted
Instructions
- Preheat oven to 350.
- Spray a 9x13 baking pan with non-stick pan spray.
- Spread the chopped rhubarb in the bottom of the prepared pan.4 Cups (488 g) Rhubarb
- Sprinkle the cinnamon and nutmeg over the rhubarb.1 Teaspoon Cinnamon, ¼ Teaspoon (¼ Teaspoon) Nutmeg
- Cover the rhubarb evenly with sugar.1 Cup (200 g) Sugar
- Sprinkle the cake mix over the rhubarb and sugar. Do not press or stir.1 box Cake mix
- Sprinkle the water over the cake mix to moisten it.1 Cup (236 ⅗ ml) Water
- Drizzle the melted butter over the remaining dry parts of the cake mix.½ Cup (113 ½ g) Butter
- Cover with foil and bake for 45 minutes. Remove foil and bake an additional 15 minutes or until the top of the cake is golden brown and crunchy.
- Remove from the oven and serve with ice cream and/or whipped cream.
Connie says
If using frozen rhubard does one thaw and let it drain or use frozen?
Sarah Mock says
I would drain about 1/2 of the liquid. I would be afraid that if you drained it all, it would be too dry.... leave it all and it would be too wet. I hope that helps! ~ Sarah
Sheila says
I made this for my family and they loved it. We do serve it warm with vanilla ice cream and it’s delicious.
Sarah Mock says
OOH!! I love vanilla ice cream with this dump cake. Thanks for letting me know you enjoyed it. That means so much to me.
Jamie Yonash says
I loved rhubarb pie but had never thought about making a dump cake with rhubarb. This turns out so good and is super easy to make!