Rhubarb Dump Cake

Name: Rhubarb Dump Cake
Prep time: 5 min
Cook time: 60 min
Total time: 65 min
Ingredients: 1 lb rhubarb (fresh, cut into 1" chunks); 1 pkg strawberry gelatin dessert (3 oz box); ¾ cup sugar; 1 pkg White cake mix (or yellow cake mix); ½ cup butter (1 stick); 2 cup water

Jump to Recipe

This easy Rhubarb Dump Cake is a fuss-free dessert made with tangy rhubarb and just five simple ingredients. Just dump, bake, and serve with a scoop of homemade vanilla ice cream for an extra treat. It's a quick, crowd-pleasing dessert, much like our Peach Dump Cake and Blueberry Lemon Bars.

pan of Rhubarb dump cake in the background with servings in two parfait glasses.

Why You'll Love This Rhubarb Dump Cake Recipe

This foolproof Rhubarb Dump Cake recipe features tangy rhubarb nestled in layers of crumbly cake and buttery streusel. It's called a 'dump cake' because all you need to do is dump the ingredients into your pan and let your oven do the work for a homemade treat.

Super easy. Simply layer the rhubarb, cake mix, butter, and water in a baking dish and bake. No mixing or stirring required!
Versatile. You can use fresh or frozen rhubarb, and you can also add other fruits, such as strawberries, blueberries, or raspberries. Canned pie filling works great too (my ex husband's family calls it Cherry Glop when canned pie filling is used)!
Delicious. The tart rhubarb is perfectly balanced by the sweetness of the cake mix and the buttery topping.

Ingredients Overview

You'll need a white or yellow cake mix, some fresh rhubarb, sugar, butter, a small box of strawberry Jello (or raspberry, cherry, anything red), and some water. This rustic delight could be on your table tonight!

Full ingredient amounts and preparation instructions are in the printable recipe card at the bottom of this post.

white cake mix, strawberry jello, butter, sugar, water, and fresh rhubarb for a cake.

How To Make A Rhubarb Dump Cake

Made with fresh or frozen rhubarb, cake mix, butter, and water, this cake is simple to throw together and always a crowd-pleaser.

Step 1: Preheat the oven to 350℉, and spray a 9 x 13 casserole dish with non stick cooking spray.

Step 2: Wash and trim the ends off the fresh rhubarb. Cut into 1" pieces and spread in the bottom of the casserole dish.

Pro Tip

If you're using frozen rhubarb or other fruit, be sure to thaw it first. You can just dump the frozen fruit into the baking dish and let it sit at room temperature for 30 minutes.

sugar sprinkled over fruit in a baking dish.

Step 3: Sprinkle the Strawberry Jello over the cut rhubarb first, then sprinkle the sugar over the Jello.

cake mix sprinkled over cut fruit in a baking dish.

Step 4: Sprinkle the dry cake mix evenly over the sugar and Jello covered rhubarb.

Butter and water drizzled over the cake mix in a baking dish.

Step 5: Drizzle the melted butter over the cake mix topped fruit mixture, then carefully pour the water over the everything.

Step 6: Bake for 45 to 60 minutes, or until the top is golden brown and bubbly.

baking dish with bubbly fruit ebbing up in the cracks of the crust.

Step 7: Remove from the oven and let cool for about 20 minutes before serving. Serve alone or with ice cream or whipped cream.

Serve warm with a scoop of ice cream or whipped cream. I hope this cake is as much a hit with your family as it was with mine!

Substitutions and Variations

Here are a few delicious variations or substitutions when making this recipe.

Cake Mix Swap: Instead of white or yellow cake mix, try a strawberry, lemon, or even a spice cake mix for different flavor combinations.
Fruit Variation: While rhubarb is classic, you can substitute or combine it with other fruits like sliced apples, peaches, or berries.
Jell-O Flavor Change: Experiment with other Jell-O flavors that complement rhubarb or your chosen fruit, such as strawberry or raspberry.

Tips for Success

Here are a few tips for making this recipe:

Don't Stir! The "dump" in dump cake is key! Resist the urge to stir the ingredients once they are in the pan. The butter melting through the dry cake mix is what creates the delicious cake-like topping.
Slice Butter Thinly: For the best results, slice your cold butter into thin pats or small cubes. This allows it to melt more evenly over the dry cake mix and moisten it thoroughly.
Check for Doneness: While the edges might be bubbly, check the center. The top should be golden brown and the fruit mixture underneath should be bubbling thickly.
Cool Before Serving: While tempting to dig in hot, allowing the dump cake to cool for at least 20-30 minutes helps the fruit filling set up, making it easier to serve and enjoy.

Storage Options

Some recommended storage options for this recipe are:

Countertop: If consumed within 1-2 days, cover the cooled dump cake tightly with plastic wrap or foil and store at room temperature.
Refrigeration: For optimal freshness and to prolong its shelf life, cover the cooled dump cake tightly and refrigerate for 3-4 days.
Freezing: To freeze, allow the dump cake to cool completely. You can freeze the entire cake in its baking dish (if freezer-safe and well-wrapped), or scoop individual portions into freezer-safe containers or bags. Freeze for up to 2-3 months. Thaw in the refrigerator overnight before reheating.

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Frequently Asked Questions

Can I add other fruits to this rhubarb dump cake recipe?

Yes, you can add other fruits to this recipe. Some popular choices include strawberries, blueberries, and raspberries.

Can I use frozen rhubarb?

Yes, you can use frozen rhubarb. Just make sure to thaw it completely and drain the excess moisture off before using.

How do I know when the cake is done?

The cake is done when the top is golden brown and the rhubarb is tender. You can also insert a toothpick into the center of the cake. If the toothpick comes out clean, the cake is done.

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