These rhubarb squares are my go-to when I want something tangy, sweet, and incredibly easy to whip up. With just three ingredients, I get a delicious treat that balances a buttery cake base with the tartness of fresh rhubarb. It’s the kind of recipe that feels like magic with minimal effort—perfect for spring and summer gatherings or just a quick dessert fix.
Ingredients
(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)
1 box yellow cake mix (or white cake mix)
1 cup unsalted butter, melted
2 1/2 cups rhubarb, chopped
Directions
I start by preheating my oven to 350°F (175°C) and greasing a 9×13-inch baking pan—or I line it with parchment paper to make removal easier.
In a large bowl, I stir together the cake mix and melted butter until I get a crumbly dough.
I press this dough evenly into the bottom of my prepared pan to create a firm crust.
Then, I spread the chopped rhubarb on top, pressing it gently into the dough.
I bake everything for 40–45 minutes, until the rhubarb is tender and the crust turns a golden brown.
Once baked, I let the whole thing cool completely before slicing into squares. I prefer serving them at room temperature or chilled.
Servings and timing
This recipe yields 12 servings.
Prep Time: 10 minutes
Cook Time: 40–45 minutes
Total Time: 50–55 minutes
Calories: 240 kcal per serving
Variations
I sometimes switch things up by using a white cake mix instead of yellow for a slightly lighter flavor. When I want more texture and sweetness, I’ll sprinkle a bit of sugar or even cinnamon sugar on top before baking. Adding chopped strawberries alongside the rhubarb makes a beautiful twist, and a drizzle of glaze on top after baking brings a little extra sweetness for special occasions.
Storage/reheating
Once cooled, I store these rhubarb squares in an airtight container at room temperature for up to 2 days, or in the refrigerator for up to 5 days. If I want to enjoy them warm, I pop them in the microwave for about 10–15 seconds. They also freeze well—just wrap each square individually and freeze for up to 2 months.
FAQs
What type of cake mix works best?
I usually go for yellow cake mix for a richer flavor, but white cake mix works well too. Both options give a soft, buttery base that pairs beautifully with tart rhubarb.
Can I use frozen rhubarb?
Yes, I can use frozen rhubarb. I just make sure to thaw it first and drain off any excess liquid to avoid making the crust soggy.
Do I need to cook the rhubarb first?
Nope, I use raw rhubarb. It bakes beautifully in the oven and softens up just right during the baking process.
Can I add other fruits?
Absolutely. I’ve added strawberries before and loved it. Blueberries or raspberries could also work well alongside the rhubarb.
What’s the best way to cut the squares neatly?
I wait until the bars are completely cool (sometimes I chill them first), then use a sharp knife cleaned between cuts for clean edges.
Conclusion
These rhubarb squares are a fantastic way to highlight the tangy brightness of rhubarb with almost no effort. I keep this recipe in my back pocket for potlucks, quick desserts, or anytime I want something nostalgic and comforting. With just three ingredients, it’s one of the easiest and tastiest desserts I make.
Recipe:
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Rhubarb Squares
- Total Time: 55 minutes
- Yield: 12 servings
- Diet: Vegetarian
Description
These rhubarb squares are an easy and delicious dessert with a tangy-sweet flavor. Made with just three ingredients—cake mix, butter, and rhubarb—they offer a soft, buttery crust and a tart fruit topping, perfect for spring and summer treats.
Ingredients
1 box yellow cake mix (or white cake mix)
1 cup unsalted butter, melted
2 1/2 cups rhubarb, chopped
Instructions
- Preheat oven to 350°F (175°C) and grease or line a 9×13-inch baking pan with parchment paper.
- In a large bowl, combine cake mix and melted butter until a crumbly dough forms.
- Press the dough evenly into the bottom of the prepared pan to form a crust.
- Evenly spread the chopped rhubarb on top, pressing it gently into the dough.
- Bake for 40–45 minutes, until the rhubarb is tender and the crust is golden brown.
- Let the dessert cool completely before slicing into squares.
- Serve at room temperature or chilled.
Notes
Use parchment paper for easy removal from the pan.
Try using white cake mix for a lighter flavor.
Add a sprinkle of cinnamon sugar or a drizzle of glaze for variation.
Store in an airtight container at room temperature for 2 days or in the fridge for 5 days.
Freeze individually wrapped squares for up to 2 months.
- Prep Time: 10 minutes
- Cook Time: 45 minutes
- Category: Dessert
- Method: Baking
- Cuisine: American
Nutrition
- Serving Size: 1 square
- Calories: 240
- Sugar: 18g
- Sodium: 220mg
- Fat: 12g
- Saturated Fat: 7g
- Unsaturated Fat: 4g
- Trans Fat: 0g
- Carbohydrates: 32g
- Fiber: 1g
- Protein: 2g
- Cholesterol: 30mg
