Easy 3-Ingredient Lemon Crumble Bars with Cake Mix

These lemon crumble bars pair a buttery cake mix crust with a sweet-tart lemon filling and a light scattering of crumbs on top. The filling stays soft and smooth, while the pressed crust gives each square a sturdy base. With just three ingredients and 10 minutes of prep, they’re an easy dessert to put together when you want something bright and lemony.

The same crumb mixture makes both the crust and topping, so there’s no separate dough to prepare. Serve these bars at a spring brunch, bring them to a summer potluck, or enjoy a chilled square after dinner. Just leave enough time for them to cool completely before slicing.

Why You’ll Love This Recipe

• Only three ingredients: Cake mix, salted butter, and canned lemon pie filling.
• Quick prep: The bars take about 10 minutes to assemble.
• No electric mixer needed: A fork or pastry cutter handles the crumb mixture.
• One mixture does double duty: Use it for both the crust and crumble topping.
• Easy to share: A 9 × 13-inch dish makes 12 bars.
• Delicious chilled: Refrigerating the cooled bars firms the filling for cleaner slices.

Equipment

• 9 × 13-inch baking dish
• Mixing bowl
• Measuring cup
• Fork or pastry cutter
• Spoon or spatula
• Knife

Ingredients

You’ll need these three ingredients, plus nonstick cooking spray to prepare the baking dish as directed.

• 1 (15.25 oz) box yellow cake mix
• ½ cup salted butter (1 stick), softened—not melted
• 1 (22 oz) can lemon pie filling

Ingredient Notes & Substitutions

Yellow cake mix: Use the dry mix straight from the box. The eggs, oil, and water listed on the package aren’t part of this recipe. Stick with the specified 15.25-ounce box to preserve the balance of crumbs and butter.

Salted butter: Softened butter should give when pressed but still hold its shape. It needs to work into the cake mix to form crumbs. Melted butter changes that texture, so use softened butter as directed.

Lemon pie filling: Choose prepared canned lemon pie filling. Dry lemon pudding mix isn’t a direct substitute and won’t create the filling described here.

No ingredient substitutions were provided for the base recipe. For the closest match, use the ingredients and amounts listed above.

How to Make Lemon Crumble Bars

1. Prepare the baking dish. Preheat the oven to 350°F (175°C). Lightly coat a 9 × 13-inch baking dish with nonstick cooking spray.
2. Make the crumb mixture. Combine the dry yellow cake mix and softened butter in a bowl. Work the butter into the mix with a fork or pastry cutter until the mixture is crumbly.
3. Reserve the topping. Measure out ½ cup of crumbs and set them aside.
4. Press in the crust. Spread the remaining crumb mixture in the prepared baking dish. Press firmly into an even layer, reaching all the corners.
5. Add the lemon filling. Spoon the lemon pie filling over the crust. Gently spread it evenly without pulling up the crumb layer underneath.
6. Add the crumble topping. Scatter the reserved ½ cup of crumbs over the lemon filling.
7. Bake. Bake for 20–25 minutes, until the crust is set and the edges look baked. The topping will stay fairly pale; don’t wait for it to turn dark brown.
8. Cool and slice. Let the lemon crumble bars cool completely in the dish before cutting into 12 bars. For firmer filling and cleaner slices, refrigerate after cooling and serve chilled.

Tips for Success

• Use softened butter. Melted butter won’t give you the crumbly mixture called for here.
• Skip the cake mix additions. Use only the dry mix, without the eggs, oil, or water listed on the box.
• Measure the reserved crumbs. Setting aside exactly ½ cup leaves the remaining mixture for the crust.
• Press the crust evenly. Pay attention to the corners so the filling has an even base.
• Spread the filling gently. Use light strokes to keep the pressed crumbs in place.
• Watch the edges, not the topping’s color. A pale crumble topping is expected with this recipe.
• Cool before cutting. For neater bars, chill after cooling and wipe the knife between cuts.

Variations

These optional serving variations leave the original three-ingredient recipe unchanged and add toppings after baking.

• Powdered sugar finish: Lightly dust the cooled bars with powdered sugar just before serving.
• Berry topping: Serve individual bars with fresh raspberries or blueberries.
• Whipped cream topping: Add a small spoonful of whipped cream to each chilled square.

How to Store

Cover the cooled bars and refrigerate them. Chilling also helps firm the lemon filling for serving.

Storage duration: [Not provided]. Follow any applicable storage guidance on the lemon pie filling package.

Freezing: Freezing and thawing instructions were not provided for this recipe.

Serving Suggestions

Serve these bars completely cooled or chilled for an easy dessert that doesn’t need much dressing up.

• Arrange them on a platter for a spring brunch or summer potluck.
• Pair a square with coffee or tea for an afternoon treat.
• Add them to an Easter or Mother’s Day dessert spread.
• Serve chilled bars with fresh berries for a simple after-dinner dessert.

Frequently Asked Questions

Do I prepare the cake mix according to the box?

No. Use only the dry cake mix. Combine it with the softened butter as directed, without adding the eggs, oil, or water listed on the package.

Can I use lemon pudding mix instead of lemon pie filling?

No. This recipe calls for 22 ounces of prepared lemon pie filling. Dry pudding mix isn’t an interchangeable ingredient.

Why is my crumble topping still pale?

That’s expected. Look for a set crust and baked edges after 20–25 minutes. Waiting for a dark brown topping could lead to overbaking.

Why are my lemon crumble bars difficult to slice?

They may still be too warm. Cool them completely in the baking dish, then refrigerate if you want a firmer filling. Wipe the knife between cuts to keep the edges neat.

Can I serve these bars chilled?

Yes. The recipe specifically suggests refrigerating the bars after cooling for firmer filling and cleaner slices.

How much crumb mixture goes on top?

Reserve ½ cup for the topping. Press all the remaining mixture into the baking dish to make the crust.

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