3 Ingredient Rhubarb Squares

3 Ingredient Rhubarb Squares make a warm, tart treat with almost no fuss. This simple tray bake fills your kitchen with a bright, fruity smell and a golden crust that feels soft and slightly crumbly under your teeth. If you need a quick family dessert that brings comfort and a little nostalgia, this is it. For other fast dinner ideas, try this 30-minute creamy chicken pasta for an easy weeknight meal.

Why Make This Recipe

• Quick & Easy: mixes and bakes in under an hour.
• Family Favorite: mild sweetness kids and adults both enjoy.
• Budget-Friendly: uses pantry staples and seasonal rhubarb.
• Low-effort: only three main ingredients and one pan.

This recipe stands out because the rhubarb adds a lively tartness that brightens the cake mix base. It feels cozy straight from the oven — warm squares with a soft crumb and a hint of tang. The taste can bring back summer memories or create new ones around your kitchen table. If you like simple recipes that still feel special, you’ll love these squares — they’re honest, homey, and satisfying. For more on simple pantry swaps, see this note about original ingredients in Rice Krispies.

Ingredients

• For the filling:
• 3 cups fresh rhubarb, chopped into 1/2-inch pieces (or thawed, drained frozen rhubarb)
• For the base:
• 1 (15.25 oz) box yellow cake mix (not pudding mix)
• 2 large eggs, beaten

Notes:

• Use firm, tart rhubarb for best flavor. If your rhubarb is very watery, pat it dry with a towel.
• Room-temperature eggs mix in easier and give a smoother batter.

How to Make 3 Ingredient Rhubarb Squares

1. Preheat the oven to 350°F (175°C). Grease a 9×13-inch baking pan or line it with parchment. (This helps the squares lift out cleanly.)
2. Toss the chopped rhubarb in a bowl and pat off any excess moisture. If using frozen rhubarb, thaw and drain well. (Removing extra water prevents a soggy center.)
3. In a medium bowl, combine the cake mix and beaten eggs. Stir until you get a thick, slightly crumbly batter. (The batter will be stiffer than cake batter — that’s normal.)
4. Press about two-thirds of the batter into the bottom of the prepared pan to form an even base. Use the back of a spoon to compact it. (This gives a firm crust to hold the filling.)
5. Spread the rhubarb evenly over the crust.
6. Crumble the remaining batter over the rhubarb in small pieces so you still see some fruit. (This creates a textured top that turns golden while baking.)
7. Bake for 30–35 minutes or until the top is golden and a toothpick in the center comes out mostly clean with a few moist crumbs. The kitchen will smell warm and fruity.
8. Let the pan cool on a rack for at least 20 minutes before cutting into squares. Cooling helps the squares set and makes them easier to slice.

How to Serve 3 Ingredient Rhubarb Squares

• Warm with a scoop of vanilla ice cream or a dollop of whipped cream for a cozy dessert.
• Dust with a little powdered sugar and serve on a simple plate for tea time.
• Cut into bite-size pieces and serve on a platter for potlucks or family gatherings.

How to Store 3 Ingredient Rhubarb Squares

• At room temperature: Keep in an airtight container for up to 2 days.
• In the fridge: Store in an airtight container for up to 5 days. Bring to room temp or warm gently before serving.
• Freezing: Wrap slices tightly in plastic and place in a freezer bag for up to 2 months. Thaw in the fridge overnight and warm in a low oven (300°F / 150°C) for 10–15 minutes.

To reheat, place squares on a baking sheet in a 325°F (160°C) oven for 8–10 minutes, or microwave a single piece 15–25 seconds until warm.

Tips to Make 3 Ingredient Rhubarb Squares

• Cut rhubarb into even pieces so it bakes uniformly.
• Pat rhubarb dry if it looks wet to avoid a soggy middle.
• Press the base firmly for a firmer crust that holds the filling.
• Let the bars cool well before slicing to get neat squares.

Variation

• Gluten-free: Use a gluten-free yellow cake mix in place of regular cake mix.
• Sweeter version: Sprinkle 1–2 tablespoons of sugar over the rhubarb if your stalks are very tart, or fold in 1/2 cup chopped strawberries for a rhubarb-strawberry twist.

FAQ 1 — Can I use frozen rhubarb?

Yes. Thaw it fully and drain off excess liquid, then pat dry with paper towels. Using thawed and drained rhubarb keeps the squares from getting too wet.

FAQ 2 — Can I use a different cake mix flavor?

You can. Yellow or white cake mixes work best for a neutral base. Avoid chocolate unless you want a very different flavor profile.

FAQ 3 — How do I know when they are done?

The top should be golden and a toothpick in the center should come out with a few moist crumbs but not raw batter. The edges will pull slightly from the pan.

FAQ 4 — Can I add spices?

Yes — a pinch of cinnamon or nutmeg (1/4 to 1/2 teaspoon) mixed into the batter adds warmth without changing the simple nature of the recipe.

Conclusion

These 3 Ingredient Rhubarb Squares are a simple way to bring a warm, tangy dessert to your table with very little fuss. They bake up with a soft, golden crumb and a fresh, slightly tart rhubarb flavor that feels both comforting and bright. If you enjoyed this easy tray bake, you might also like this Easy 3 Ingredient Rhubarb Cake (A 35 minute recipe!) for another quick rhubarb idea. Please leave a comment and a star rating to tell us how they turned out, and share on Pinterest or Facebook so friends can try them too. What twist did you try? Let us know below!