Irresistible Rhubarb Dump Cake in Just 5 Ingredients

Oh my gosh, you have to try this rhubarb dump cake—it’s the easiest, most delicious dessert you’ll ever make! I swear, every time I bring this to family gatherings, people go crazy for it. There’s something magical about how the tart rhubarb, sweet sugar, and buttery cake mix come together with almost zero effort. Just dump, bake, and boom—you’ve got a dessert that tastes like you slaved over it all day.

I first discovered this recipe when my neighbor brought over a pan after my son was born. One bite and I was hooked! Now it’s my go-to when rhubarb season hits. The best part? You probably have all the ingredients in your pantry right now. No fancy techniques, no complicated steps—just pure, comforting goodness that makes your kitchen smell amazing.

Why You’ll Love This Rhubarb Dump Cake

Trust me, this recipe is a game-changer for so many reasons:

• Effortless prep: Just layer and bake—no mixing bowls required!
• Pantry staples: Only 5 simple ingredients you likely have on hand
• Perfect balance: The tart rhubarb and sweet topping create magic together
• Crowd-pleaser: I’ve never brought home leftovers from a potluck
• No-fail: Even beginner bakers get perfect results every time

Seriously, it’s the dessert that keeps on giving—warm from the oven, room temperature, or even cold the next day (not that it ever lasts that long in my house!).

Ingredients for Rhubarb Dump Cake

Here’s the beautiful simplicity of this recipe – just five basic ingredients create something extraordinary. I always tell my friends: “Don’t overthink it!” Here’s what you’ll need:

• 4 cups chopped rhubarb – fresh gives the best texture, but frozen works too (no need to thaw!)
• 1 cup granulated sugar – this balances the rhubarb’s natural tartness perfectly
• 1 box (15.25 oz) yellow cake mix – the classic choice, though I’ve experimented with others
• 1/2 cup butter – melted, and yes, it must be real butter for that golden crust
• 1 cup water – just plain water creates the perfect saucy base

See? Nothing fancy – just honest ingredients that transform into something magical in the oven. I’ve made this with everything from garden-fresh rhubarb to last year’s frozen stash – it always works!

How to Make Rhubarb Dump Cake

Okay, here’s where the magic happens! I promise this is so easy you’ll laugh. Just follow these simple steps, and you’ll have a dessert that’ll make everyone think you’re a baking genius.

Step 1: Prepare the Rhubarb Layer

First things first – preheat that oven to 350°F (175°C). While it’s heating up, grab your 9×13-inch baking dish and give it a quick grease. I use butter for this – just a light coating so nothing sticks. Now toss in those 4 cups of chopped rhubarb and spread them out evenly. No need to be perfect, but try to avoid big clumps in one spot.

Step 2: Add Sugar and Water

Here’s the fun part – sprinkle that cup of sugar right over the rhubarb like you’re making it snow! Then gently pour the water over everything. And here’s my secret – don’t stir! The water will help dissolve the sugar and create this amazing syrupy base as it bakes.

Step 3: Layer Cake Mix and Butter

Now take your box of yellow cake mix and sprinkle it evenly over the top. I like to use my fingers to break up any big clumps. Then drizzle that melted butter all over – I usually do it in a zigzag pattern to cover as much as possible. Pro tip: If you’ve got some dry spots, just tilt the pan a bit to help the butter spread.

Step 4: Bake to Perfection

Pop it in the oven and let the magic happen! In about 45 minutes, you’ll see the top turn this gorgeous golden brown, and you’ll smell that amazing buttery-sweet aroma. The edges should be bubbling slightly – that’s when you know it’s done. Let it cool for 10-15 minutes before serving (if you can wait that long!).

Tips for the Best Rhubarb Dump Cake

After making this rhubarb dump cake more times than I can count, I’ve picked up some tricks that take it from good to “Oh my gosh, give me the recipe!” good:

• Butter temperature matters: For an extra crispy topping, try using cold butter cut into small pieces instead of melted. It creates these delicious buttery pockets in the cake mix.
• Ice cream is mandatory: Serve it warm with vanilla ice cream melting over the top – the hot-cold combo is heavenly!
• Taste your rhubarb first: If it’s super tart, add an extra 1/4 cup sugar. Too sweet? Cut back a bit.
• Don’t peek! Resist opening the oven door until at least 40 minutes in – that steam is working its magic.

These little tweaks make all the difference between a good dump cake and the kind that disappears before it even cools!

Variations on Rhubarb Dump Cake

Oh, the fun you can have with this recipe! Once you’ve mastered the classic version, try these delicious twists that keep things exciting:

• Strawberry-rhubarb magic: Swap half the rhubarb for sliced strawberries – the perfect sweet-tart combo my grandma used to make
• Spice it up: Use spice cake mix instead of yellow for a warm, cozy flavor that pairs beautifully with rhubarb
• Crunchy topping: Mix 1/2 cup chopped pecans or walnuts into the cake mix before sprinkling for extra texture
• Vanilla dream: Try vanilla cake mix and add a teaspoon of almond extract to the water – smells incredible while baking!

The best part? You can’t mess it up – each variation brings its own special charm to this already amazing dessert.

Serving and Storing Rhubarb Dump Cake

Here’s my favorite part – digging into that warm, bubbly rhubarb dump cake! I always serve it straight from the pan with a big scoop of vanilla ice cream melting over the top. Whipped cream is fantastic too – the fluffy sweetness cuts through the tart rhubarb perfectly. Leftovers? Just cover the pan tightly and refrigerate for up to 3 days. To reheat, pop individual servings in the microwave for 30 seconds or warm the whole pan in a 300°F oven for 10 minutes. Pro tip: The flavors actually deepen overnight, making day-two servings extra delicious!

Rhubarb Dump Cake FAQs

I get asked these questions all the time, so let me save you some trouble with my hard-earned rhubarb wisdom!

Can I use frozen rhubarb?
Absolutely! Frozen works great – just chop it while still slightly frozen (easier to handle!) and use it straight from the freezer. No need to thaw, but you might need an extra 5 minutes baking time.

Can I reduce the sugar?
You can, but be careful – rhubarb is tart! I’d start with just 1/4 cup less sugar max. Taste your rhubarb first – super tart stalks might need all that sweetness.

How do I avoid a soggy cake?
Two tricks: 1) Don’t stir after adding water – let the layers work their magic. 2) Make sure your oven is fully preheated so the topping crisps up properly.

Can I make this ahead?
Yes! Assemble it, cover tightly, and refrigerate overnight. Just add 5-10 minutes to the bake time since it’s going in cold.

Why is my topping dry in spots?
You might not have drizzled the butter evenly. Next time, melt a little extra butter and keep some handy to spot-treat any dry areas before baking.

Nutritional Information

Now, I’m no nutritionist, but here’s the general scoop per slice (based on 12 servings): about 250 calories, 10g fat (6g saturated), and 25g sugar. It’s dessert, after all! These are rough estimates since rhubarb sizes vary and cake mixes differ slightly. The good news? Rhubarb packs fiber (2g per serving) and vitamin K, so we’re not totally indulging guilt-free… just mostly!

Final Thoughts

There you have it – my foolproof rhubarb dump cake that never fails to impress! I’d love to hear how yours turns out. Tag me if you make it, and don’t be surprised when friends start begging for the recipe. Happy baking!

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