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Bright Lemon Sheet Cake with creamy lemon buttercream frosting is a sunny dessert perfect for feeding a crowd!

Of all the Lemon Cakes I have recipes for, this Lemon Sheet Cake just might be the easiest of them all! It’s moist just like our Lemon Buttermilk Cake and has a delicious frosting like our Lemon Bundt Cake.

Moist Lemon sheet Cake served on a white plate.

a lemony dessert for spring & summer

Spring makes me think of fruit and lemons and the dessert we are sharing today – Lemon Sheet Cake!

This Lemon Pudding Cake with Lemon Frosting is one of the easiest Lemon Cake Recipes you will ever make! It’s similar to our Chocolate Sheet Cake, kind of a Lemon Texas Sheet Cake!

We started with a lemon cake mix from a box – so simple! It also has a pudding mix in it, which makes it so good. Because of the added pudding and buttermilk mixture, the texture will be more dense and moist than a regular cake, and a bit fudgy like a brownie.

The best part is the lemon buttercream frosting on top. This Lemon Sheet Cake Recipe is SO delicious and creamy!!

The lemon flavor is a perfect dessert for Spring and Summer!!

Pudding boxes and cake mix boxes for lemon sheet cake.

Lemon cake from a mix

The reason this is an EASY Lemon Cake is that it’s not made totally from scratch.

You actually use a box mix plus some instant pudding and buttermilk to make it even more scrumptious!

PREP. Preheat oven to 350°F.

DRY INGREDIENTS. Add lemon cake mix and pudding mix to a medium bowl.

WET INGREDIENTS. Add buttermilk plus the ingredients on the back of the cake mix box to the cake mix and pudding mixture and beat until well combined.

BAKE. Pour the cake batter into a greased 9×13 pan. Bake for 23-35 minutes (or for more slices and thinner cake, use an 11×15 pan and bake for 18-20 minutes).

COOL + FROST. While the cake is cooling, make the cream cheese frosting by creaming together butter and cream cheese.

Add powdered sugar, vanilla, Jell-o mix (gelatin), lemon juice, lemon zest, and milk. Whisk until smooth.

Frost the cake and ENJOY!

Lemon sheet cake mix poured in bowl.

Recipe Tips

Lemon zest. Making lemon zest is very simple. Wash the lemon. Zest before juicing.

Using a grater or a traditional zester, simply rub the lemon against the blades of the grater or zester, making sure to only grate the outermost peel of the lemon. Zesting adds great citrus flavor!

Cake mix. I used a 15.25 box of lemon cake mix. The ingredients on the back included 1 cup water, ½ cup vegetable oil, and 3 large eggs. Purchase a cake mix that is similar in size and purchase the ingredients that are listed on the back of the box.

Pudding. Substitute the white chocolate pudding mix with a vanilla-flavored instant pudding mix. Sugar-free pudding also works just fine! Be sure that it is the instant kind and only use the pudding powder in the recipe, DO NOT make the pudding.

Toppings. 

Lemon sheet cake batter mixed in glass bowl.

Sheet cake tIPS

A traditional sheet cake is a rectangular single-layered cake. It can vary in length and width, but it is usually about 2 inches in height. Easily make a double-layered sheet cake. 

The ingredients of a sheet cake are often the exact same as round cakes or layered cakes.

Different-sized pans. A half sheet cake is 9×13 inches, a medium sheet cake is 11×15 inches, and a large sheet cake is 12×18 inches.

One trick to make a larger sheet cake is to bake 2-3 smaller cakes, place them side by side on a serving tray, and frost them as if it is one large cake. 

  • Large sheet cake. Make the cake a little thinner and use an 11×15 pan to get more slices out of it. The estimated cook time is 17-20 minutes.
  • For smaller-sized pans and circle pans, adjust the cook time to about 35-40 minutes, or until a toothpick poked into the center comes out clean. The cake may have a rounder top. As it cools it will flatten as seen in the recipe video.

Sheet cake servings are usually cut party size 1½x2 inch, or wedding size 1×2 inch.

Spreading frosting onto cooled lemon sheet cake.

Storing Info

Make ahead of time. Assemble the cake completely and cover the top with a lid or plastic wrap and leave it in the fridge. Take it out of the fridge 2 hours before it’s served to let it come to room temperature.

  • To avoid the cake from drying out, store it (without frosting) covered with plastic wrap, at room temperature.
  • Make the Lemon Cake Icing right before serving. If made beforehand, store the frosting in the fridge in an airtight container. Take it out 2 hours before frosting the cake so it can come to room temperature and go on smoothly.

STORE leftovers covered with plastic wrap in the fridge for 5-6 days. Take it out of the fridge an hour before serving to give the frosting time to get to room temperature.

Do not store this cake at room temperature for longer than 8 hours because of the cream cheese in the frosting.

FREEZE the Lemon Sheet Cake before or after frosting it.

  • To freeze unfrosted. Wrap the cooled cake with plastic wrap and again with foil. Freeze for up to 3 months. Unwrap before thawing. The frosting can be frozen in a separate container for 3-4 months. Thaw before using.
  • Freeze the frosted cake whole, or in slices. Place the cake in the freezer until the frosting has hardened, then wrap it with plastic and foil. The cake is best when eaten within 3- 4 months, but can last for 5-6 months. 
Homemade lemon sheet cake with lemon frosting on a white plate.

Recipe FAQ

What size box of cake mix should I use?

I used a 15.25 box of lemon cake mix, specifically Duncan Hines. Purchase a box of cake mix that is similar in size and make sure you also have the ingredients that are listed on the back.

What should I use if I can’t find white chocolate pudding?

If you can’t find white chocolate flavored pudding, I would use vanilla or lemon flavored. Make sure it’s the instant pudding!

Why did my cake fall? Why is it dense/soupy?

One of the main culprits is buying a cake mix that already has pudding in it. Make sure your box of cake mix does NOT already have pudding. Or, if it does, omit the instant pudding mix when making the cake batter.

And for more lemon treats:

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4.87 from 60 votes

Lemon Sheet Cake Recipe

By: Lil’ Luna
Bright Lemon Sheet Cake with creamy lemon buttercream frosting is a sunny dessert perfect for feeding a crowd!
Servings: 24
Prep: 10 minutes
Cook: 25 minutes
Total: 35 minutes

Ingredients 

Cake

  • 1 box lemon cake mix plus ingredients on box
  • 1 cup buttermilk
  • 3 oz white chocolate instant pudding mix

Frosting

  • 1/4 cup butter softened
  • 4 oz cream cheese softened
  • 2 cups powdered sugar
  • 2 tbsp lemon jello mix
  • 1 tsp vanilla extract
  • 1 tbsp lemon juice you can use more if you want more lemon taste
  • 2-3 tsp lemon zest
  • 1-2 tbsp milk
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Instructions 

  • Preheat oven to 350°F.
  • Add lemon cake mix and pudding mix to a medium bowl.
  • Add buttermilk plus the ingredients on the back of the cake mix box and beat until well combined.
  • Pour into a greased 9×13 pan. Bake for 23-35 minutes (or for more slices and thinner cake, use an 11×15 pan and bake for 18-20 minutes.
  • While the cake is cooling, make the frosting by creaming together butter and cream cheese. Add powdered sugar, vanilla, jello mix, lemon juice, lemon zest, and milk. Beat until smooth.
  • Frost cake and ENJOY!

Video

Nutrition

Calories: 174kcal, Carbohydrates: 32g, Protein: 1g, Fat: 4g, Saturated Fat: 2g, Cholesterol: 11mg, Sodium: 225mg, Potassium: 30mg, Sugar: 23g, Vitamin A: 140IU, Vitamin C: 0.5mg, Calcium: 63mg, Iron: 0.5mg

Nutrition information is automatically calculated, so should only be used as an approximation.

Additional Info

Course: Dessert
Cuisine: American
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Share it with us on Instagram using the hashtag #lilluna, so we can see what you’re creating in the kitchen!

About Kristyn

My name is Kristyn and I’m the mom of SIX stinkin’ cute kids and the wife to my smokin’ hot hubby, Lo. My mom’s maiden name is Luna, and I’m one of the many crafty “Lil’ Lunas” in the fam. On this site I like to share all things creative - from recipes to home decor to gifts and home decor ideas. Welcome!

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Recipe Rating




111 Comments

  1. MARTHA says:

    Please put the Weight of cake mix when including in recipes. Think they aRe down to 15.25 ounces now. I keep a vanilla cake mix in pantry to supplement the mix in recipes indicating the larger size boxes. Please clarify on this recipe what ounce box you are meaning.
    Thanks

    1. Kristyn Merkley says:

      Usually the boxes are the same size, so I don’t specify the size/weight.

  2. Madeline says:

    4 stars
    Just made this cake and have not frost it yet. But I noticed that it sunk a little in several places. I have not had this happen before with a cake mix. Also tHe frostiNg tastes good but its A little gritty. Any ideas why these things happened?

    1. Kristyn Merkley says:

      I really wish I knew. There are reasons a cake might sink & I’m not saying you did them, but it’s hard to know…undermixing, incorrect amounts of ingredients, moving the cake while baking, etc. I’m sorry it did. If my frosting gets too gritty, I just add a little more powdered sugar.

  3. Amber Perona says:

    Do do you think it makes a difference if I use a cake mix that says that already has pUdding in it?

    1. Kristyn Merkley says:

      I wish I knew for sure. I personally haven’t tried. I guess one way to find out?!

  4. Sandy p. says:

    4 stars
    I love this cake. I am still having problems with cook time and it collapsing in the middle when I remove it from oven. I used Duncan Hines lemon cake mix. Your directions say to use ingredients on back of box. Plus add 1 cup buttermilk and white chocolate pudding mix. The ingredients on back of cake mix are 1 cup water, 2 eggs and oil. I wonder if you use a different cake mix and don’t include 1 cup of water and 1 cup of buttermilk. Also with your pan size, the chocolate sheet cake recipe calls for a 10 X 14 jelly roll pan. For lemon cake you say 9 x 13. Just want to clarify as I am doing something wrong. I baked it for 35 minutes. Beautiful. 10 minutes later it fell in meddle.

    1. Kristyn Merkley says:

      I can’t remember what mix I used, but they should all be similar & yes, I did use all the ingredients. This cake is in the 9×13 🙂 I’m really not sure what made it fall?? I’m sorry it did! Did you add the pudding mix?

  5. Erika says:

    Do i frost while hot or after it has cooled?

    1. Kristyn Merkley says:

      After it has cooled 🙂 Enjoy!!

  6. Jackie says:

    5 stars
    I FollOwed this recipe as recommended by one of the reviewerS with the duncan hines box of lemon cake with the Hersheys white chocolate pudding ! It came out perfecf ! I baked it in 2 9 inch pans for a round cake and had to bake it For About 40 minutes. It was delIcious and moiSt ! My husband and kids loved it ! For sure dont get a box of cake that already has pudding mix dded 🙂

    1. Kristyn Merkley says:

      So, glad you liked it! Thank you for sharing that!

  7. Doug says:

    THIS IS THE FIRST CAKE I HAVE MADE. I HATE DRY CAKE SO I WANTED A RECIPE FOR A MOIST CAKE. IT TURNED OUT GREAT. I FORGOT IT WAS IN THE OVEN SO I COOKED IT FOR 45 MINUTES, WHICH WORKED OUT PERFECTLY ACTUALLY. family DEVOURED IT.

    1. Kristyn Merkley says:

      I am so happy to hear that! Hopefully, you like cake now 😉 Thank you!

  8. Erin says:

    I thought a sheet Cake was cooked in an 11×14 pan…. is that why people’s cakes are falling? What size pan should I use?

    1. Kristyn Merkley says:

      I used a 9×13 & it turns out perfectly 🙂

      1. Jess says:

        Hello! I am curious what your thoughts are trying a lemon pudding instead of the white chocolate? I want it to be super lemony!
        Thank you!

  9. Katie says:

    5 stars
    This recipe is excellent. I made it for work and everyone loved it and was gone quickly. I made it 2 days ago and now I’m making it again for my family. This is going to be a staple. I used the Duncan Hines lemon signature box of cake mix and the hershey’s brand of white chocolate pudding mix and did everything as directed in above recipe. I read the other comments and made sure to bake 35 minutes and came out perfectly. 25 minutes wasn’t long enough. I would highly recommend this recipe and normally dont comment but wanted to help others know this is a great cake.

    1. Kristyn Merkley says:

      Thank you for commenting!! I am glad it is a staple 🙂

  10. barbara Phillips says:

    Why does my cake seem heavy? More like a pudding. Maybe we need to cut the water?

    1. Kristyn Merkley says:

      I am not sure?? It is normally a pretty light cake. I wish I knew what happened?

      1. Pat says:

        I think i know why cake fell & is heavy! Many cake MIXes have pudding mix alreafy in them, that would be double pudding mix!
        Use cakemix w/ out pudding already in the mix, just use plain caKe mix & then u can add pudding miX! Going to try it now!7

      2. Kristyn Merkley says:

        Hope it turned out!!