These 5-ingredient Lemon Bars are the perfect combination of sweet and tart. Made with boxed cake mix and sweetened condensed milk, this is an easy version of a classic dessert!

stack of cake mix lemon bars

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Love lemon bars? You are definitely going to fall for this recipe for lemon bars that’s made super easy by using a boxed cake mix! Plus, it’s ready in less than 30 minutes so it’s perfect for a quick last-minute dessert that you can whip up whenever the craving strikes.

Lemon bars are always quick to disappear when you bring them to a potluck or picnic, and they’re so portable and cheerful with a bright yellow pop of color. I am a big fan of lemons, and this includes lemon desserts—so lemon bars are in regular rotation in my kitchen.

easy lemon dessert with one piece missing

Easy Cake Mix Lemon Bars Recipe

Ina Garten’s lemon bars have always been a favorite, and I decided to come up with a recipe that tastes just as good but is made in half the time and with hardly any ingredients! Best of all, you just need basic pantry staples, including a box lemon cake mix and condensed milk. Then you add butter, eggs, and lemon juice to create buttery, tender, lemon bar perfection.

My version of lemon bars are not exactly like your traditional lemon bars, which are made with a shortbread crust, but they sure are good. In this recipe, the cake mix makes a quick, no-fuss lemon base that’s topped with a mix of sweetened condensed milk and lemon juice. You can definitely use bottled juice if that’s all you have, but I highly recommend freshly squeezed lemon juice to infuse these bars with loads of lemon flavor. These bars also freeze well, so you can enjoy your favorite lemon treat whenever you like.

Love lemons as much as I do? Try my Lemon Cookies or Lemon Bundt Cake recipes!

Ingredients for Lemon Bars

  • Lemon Cake Mix – You can use your favorite brand of boxed cake mix, just make sure that it’s lemon flavored.
  • Butter – Use unsalted butter.
  • Egg
  • Sweetened Condensed Milk: You’ll need one can of sweetened, condensed milk.
  • Lemon Juice – Fresh lemon juice gives the best flavor, but you can also use bottled lemon juice.
step by step photos on how to make easy lemon bars

How to Make Lemon Bars

  1. Mix together the ingredients: Preheat the oven to 350°F and have a 13×9″ baking pan ready. In a bowl, mix together the cake mix, butter, and egg.
  2. Add the batter to the pan: Spread the cake mixture evenly across the bottom of the baking pan. You may need to use your hands to pat down the batter.
  3. Make the topping: In a medium bowl, whisk together the sweetened condensed milk and lemon juice. Pour the mixture over the top of the cake mix mixture in the pan.
  4. Bake: Bake the bars for 23-27 minutes. Allow to cool completely before cutting into bars.

Quick Tip

To cut the bars without too many crumbs, dip your knife in warm water, then dry the knife on a clean kitchen towel before using it to cut into the lemon bars.

stack of cake mix lemon bars

How to Store Lemon Bars

Store the bars in an airtight container in the fridge for up to 5 days. You can also freeze lemon bars. Cut the bars into squares and place them onto a baking sheet. Place it in the freezer and freeze for 1 hour. Then individually wrap the bars tightly in plastic wrap, place them in a freezer-safe bag, and store in the freezer for up to 3 months.


How do you cut lemon bars neatly?

To make perfect, neat cuts on your lemon bars, have a bowl of warm water nearby while you’re cutting the bars. Wet the knife in the warm water, wipe it clean with a dry dish towel, and make one cut. Repeat the process until the lemon bars are completely cut.

How many bars does a 9×13 pan make?

A 9×13-inch pan will make 12 2 1/10×4 ½-inch rectangles. Here’s how to make the cuts: On the long side of the pan, make a mark and cut down every 2 1/10-inches, so you have 6 columns. Turn the pan to its shorter side and make one cut down the middle, 4 ½-inches from the edge.

How long can lemon bars sit at room temperature?

Lemon bars are fine to keep out at room temperature for up to 6 hours or so.

lemon square on a metal spatula

More Easy Cake Recipes

stack of cake mix lemon bars

Lemon Bars

These 5-ingredient Lemon Bars are the perfect combination of sweet and tart. Made with boxed cake mix and sweetened condensed milk, this is an easy version of a classic dessert!
4.17 from 18 votes
Course: Dessert
Cuisine: American
Servings: 24
Prep Time: 5 minutes
Cook Time: 25 minutes


  • 1 box lemon cake mix
  • ½ cup butter
  • 1 large egg
  • 1 14 oz can sweetened condensed milk
  • ½ cup lemon juice


  • Preheat oven to 350°F.
  • In a bowl, mix together the cake mix, butter, and egg (it will be thick)
  • Spread the mixture evenly into bottom of a 13×9-inch baking pan. You may need to use your hands to pat it down.
  • Blend together sweetened condensed milk and lemon juice. Pour mixture over top of cake mix mixture.
  • Bake for 23 to 27 minutes.
  • Cool completely before cutting into bars.
  • Garnish with grated lemon if desired.


Calories: 85kcal | Carbohydrates: 19g | Protein: 1g | Fat: 1g | Saturated Fat: 1g | Polyunsaturated Fat: 1g | Monounsaturated Fat: 1g | Trans Fat: 1g | Sodium: 157mg | Potassium: 35mg | Fiber: 1g | Sugar: 10g | Vitamin A: 1IU | Vitamin C: 2mg | Calcium: 46mg | Iron: 1mg
Did you make this recipe?Mention @kasey_allthingsmamma or tag #allthingsmamma!

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About Kasey Schwartz

For over 15 years, Kasey Schwartz, the mastermind behind All Things Mamma, has been the ultimate go-to for mouthwatering family recipes. Her work has been featured on, Buzz Feed, Better Homes and Gardens, and more, making her your go-to mom next door for all things delicious and family-friendly.


  1. I made you 5 ingredients Lemon Bars. But as I took them out they were not set in the middle Is that normal? I let them cook the full 27 minutes.

    1. Sandra Haught says:

      Let me know if get answer

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