Upcycled Baby Food Jars: Rainbow Cake in A Jar

I have always had a hard time throwing away glass baby food jars (and after four kids, I have gone through plenty of them!).  They are so cute and sturdy, and there are so many different ways that they can be reused.

When Earth911.com asked if I could come up with some ideas for upcycling baby food jars, I was excited, and got to work right away!  (I am their resident craft expert this month, after winning their DIY iPad Case Contest).  I have had so much fun coming up with great uses for these little jars, that I decided to devote a whole week to them.
So be sure to visit daily for new baby food jar inspiration!

OK, on to today’s project!!
Today I want to share with you a fun (and delicious!) way to upcycle your baby food jars- bake a cake in them!!  
Cake in a Baby Food Jar, Upcycled Baby Food Jars, by Make Life Lovely
Who can resist a piece of colorful cake that is baked up and served in a cute little jar?!?  Not me.The cake colors can be customized to fit the occasion, party colors, favorite colors, etc., and is a great way to regulate the amount of cake a child eats.  One jar per kid.

Plus, it saves on time if you serve them at a party- you don’t have to cut and serve the cake on the spot!  You can bake them a day or two ahead of time, and then they day of the party you don’t have to worry about the cake, which I love.
Here’s how I made my Cakes in Upcycled Baby Food Jars
  • Cake Mix (I used 2 boxes of Betty Crocker vanilla)
  • Food Coloring (I used the gel colors- they come out brighter than the liquid kind)
  • Baby Food Jars

1.  Heat oven to temperature on cake mix box.  Mix up your cake mix according to the directions on the box.  Depending on how many jars you need, you can make 1 or 2 (or more) boxes.  Decide which color(s) you would like your cake to be, and split the mix into separate bowls, one for each color.  Add a little gel food coloring to each bowl, and mix thoroughly.
2.  With a spoon, carefully fill each jar no more that HALFWAY with cake mix.  Trust me, do NOT fill it up more than halfway!  You can do all one color, or mix it up by layering multiple colors on top of each other.  Rainbow colors are fun, too!  Place jars on a baking sheet, and bake for approx. 15-20 minutes.  Check them at 15 minutes, and continue checking, until they are thoroughly cooked.
P.S.  If you filled them too high and the cake overflowed out of the jar, just take a butter knife and cut off the top part when it is cool enough to handle.  Not that I know from experience or anything ;)
No more than halfway!
3.  Let them cool, and then place the lid securely on each jar.  These should last for a few days, if they aren’t eaten by then.


Now that your cakes are all made, you can leave the jars as is, or you can decorate them if they are for a party or special occasion.  I piped some frosting on the cake, and added some rainbow sprinkles.

Aren’t they cute?  Hope you enjoyed this!  I’ll be making these for my son’s second birthday party later this year, because I love the portion size.  Leave a comment and tell me what you think!!

Here are the other baby food jar ideas I came up with… be sure to check them out too!!


You might also like these DIY serving dishes I created from dollar store items!

I used the same rainbow cake concept for my daughter’s Under the Sea party cake using different colors of blues.

You can check out the entire under the party here for tons of ideas that you can use for an ocean or mermaid party, too!

You can also use tape to decorate inexpensively!  See how I did it for my daughter’s Minnie Mouse birthday party here.

If you liked this project, please follow me on FacebookTwitterPinterest, Bloglovin’, and Instagram.
Please share and pin!

XO, Laura

Linking Up Here:  Tatertots & JelloLil LunaSkip to my Lou, Craft-O-Maniac, Mad in Crafts, Sugar Bee Crafts, Not Just A Housewife, Someday Crafts, A to Zebra Celebrations, House of Hepworths, Reasons to Skip the HouseworkOasie Moats, The 36th Avenue, Whipperberry

Let's Be Friends!


  1. says

    I’ve made these before in mason jars but when I made them without water in the bottom of the pan the cake appeared discolored/brown on the edges. Wonder what I did wrong? Or perhaps its because the mason jars are bigger? Hmmm…?!? Now when I make them, I put them in a 9×13 cake pan and put about an inch of water in the bottom of the pan.


    • says

      I didn’t use any water at all, and I only had one turn a little brown around the edges- it was one I made with white cake mix. I think you don’t need the water because these jars are a lot smaller, so the cake cooks faster and all the way through. One less step to mess with when you cook them in baby food jars!

      Hope you give them a try!

  2. says

    These are the cutest thing ever! I love the baby food jar size. A lot of the other cakes in jars are way too big. Thanks so much for sharing. Have a great day!

  3. says

    Just avoided a birthday catastrophe- my oven died during my daughter’s birthday slumber party for a friend. All her friend wanted was a rainbow cake- Yay! but my oven decided that was a good night to die. Boo! Had all the batter colored and in greased cake pans ready to go…when the oven wouldn’t heat. So, I buttered some pint mason jars and spooned in the batter just like you did here. With no oven I had to improvise. I microwaved them. a minute and a half. 1:30. That was all it took and they came out Great! Felt a little like a mommy-rock-star. The babyfood jars would probably be done in a little under a minute. I filled my jars 3/4 full and they extruded out the top like yours did- so your No more than half way full of batter rule is 100% right. Although the magic through the microwave door was pretty spectacular. Just thought I’d share- great job on your posts!! I’ll stick to baking in the oven but it’s good to know that the microwave can work in a pinch with fantastic results! Happy Spring!

    • says

      Wow, way to save the day!! I had no idea you could microwave cake in a mason jar! So smart of you. Ha, yes, don’t fill it more than halfway. I was the guinea pig for everyone, so don’t make my same mistake ;)

      Thanks so much for sharing your experience! I’m impressed.

  4. says

    Having a 7th birthday party for my son this year with an Army theme. Can’t wait to try this with camo colors and dark green frosting on top. Maybe even throw some plastic army guys on there. Thanks for the ideas!

  5. says

    How many baby food jars did two cake mixes make? Did you use the 6 ounce jars? I am making these for our Teacher Appreciation Luncheon on Friday! Our theme is “We are Lucky to Have Our Teachers!” Love this idea! Thanks for all the ways to use all the baby food jars! My hubby will be thrilled to have them gone! :)

    • says

      Ha, my husband was happy to say adios to a lot of my jars, too! Good questions- I used the 4 oz. jars, but I’m sure it would work with the 6 oz. jars, too. I’d recommend the 4 oz. though if you have them, just because the cake cooked so perfectly and evenly in this size, and I haven’t tried the other size yet. Because it is a little bigger, just make sure that it is all the way cooked through the middle before you take them out of the oven. If you try that size, be sure to come back and let me know how it worked for you!

      I’m trying to remember how many cakes 2 boxes of cake mix made…. at least 25! My kids were eating them up as I went, and I added way too much cake to mine (as you could see from the pics), so if you only filled each jar to the halfway point, you will definitely get more than that! Good luck! As a former elementary school teacher, I can say that I would LOVE to get one of these cute little cakes for Teacher Appreciation Day :) Sorry for the novel of a comment, hope it helped!

    • says

      I didn’t have any of the 4 oz jars (I ‘m not sure where they disappeared to…) but the 6 oz jars worked great. I made them last night and they look so cute. I can’t wait to add the icing and sprinkles! I think we made 22, filling them halfway. (Two boxes was plenty.) They cooked very nicely and taste great! (We HAD to sample 1 or 2 to make sure they turned okay! :) ) I am excited to see the teachers’ reactions tomorrow. Thank you, again, for the great ideas!

    • says

      Well of course you had to sample one or two! I love that you made this for the teachers, I’m sure they loved it. Good to hear that this worked well for the 6 oz. jars, thanks for sharing your experience!!

  6. says

    The jars wont break from the heat, right? Lol. Is there any precautions to take to ensure or will they be fine? Im just worried with my luck that id have an explosion :-p. I wanna make some…fill a lil less than half so i can put a lol icing on before the lid…and then freeze so i can have a small piece of cake whenever i have the hankering :-p. Love your other projects too….esp them as lil flower vases on a board….pretty sure i HAVE to have my husband make me one for on our porch…lol

    • says

      No, the jars won;t break from the heat. They should be just fine! Yes, definitely fill less than half!! This is key to the cake not overflowing! I didn’t try freezing mine, because I don’t think you’re supposed to put glass in the freezer? I’d check first just to make sure. Thanks for reading, and good luck!

  7. says

    These are truly adorable! And what a great idea for portioning birthday cake and not having to worry about the cake-cutting when you can just enjoy the party and guest of honor! I have a bunch of baby food jars saved so I may have to try this :-).

  8. Anonymous says

    Im making these in a few days for my daughters.4th birthday. Im excited to see how they turn out. Im going to do princess theme. The.girls will get primcess colors boys are getting prince colors

    • says

      All glass baby food jars can go in the oven from my experience. I have made these many times and have never had a problem. And no explosions or bursts :) Good luck with these, they’re really fun to make!

  9. Anonymous says

    This is such a cute idea! I can’t wait to try it! What utensil do you use to eat it? Does a fork or spoon work, or do I need to use something smaller? Also, I’m doing a sunshine theme party for my daughter’s birthday. If I use yellow for the bottom layer, will it discolor or turn brown or do you suggest I use a darker color at the bottom to “mask” any browning that may occur? Thanks!

    • says

      A fork or spoon works just fine! Yellow would probably be okay… maybe try baking one just to be sure? I would go for a brighter, more vibrant yellow, because it will have less of a likelihood of browning. Good luck with your daughter’ party!

  10. says

    Cute Cute Cute! Love it! I hate throwing away baby food jars too! I always think, “i could use these for something…” I just never know what! Now I have some good ideas! Thanks!

  11. Anonymous says

    You could scoop out a little cake in the middle and fill the space with icing. Then, use a caulk gun to decorate the lid with fake icing. I saw both of these ideas on pinterest,so I can only take credit for combining the two ideas. :)

  12. Anonymous says

    I love this im going to make for my daughters, 1st birthday green and ping starwberry shortcake colors.. Now a qquestion i have a small counter top convection oven, will that work??? I dont want a armagedon in my kitchen. Thanks for the amazing ideas keep them coming

  13. Anonymous says

    What Did You Use To Put The Batter In The Jars? I was Planning on Doing THis For My Sons First Birthday And Did A Trial Run Last Night And The Colors Ran Together And SOme Didn’t Meet The Edge Of The Jar. I’m Totally Not Creative But Was Hoping I Could Pull This Idea Off. Thanks For Your Help!

    • says

      Oh no! I just used a regular spoon to spoon a small bit at a time into the jars, which worked really well. I think as long as you don’t pour a lot in at once, the colors should stay separate like mine did. Good luck!

  14. says

    for some reason my purple came out really dull…almost like a gray. I too am also wondering what you used to scoop/pour the batter into the jars. I did a trial and had a very difficult time making them look presentable. I used half pint jars instead of the small babyfood jars. I thought perhaps the smaller jars were too small…anyone else use larger jars?

    • says

      What knid of food coloring did you use? The gel colors are all I’ve used, and every time I’ve made these they have looked great. Maybe if you try using the gel colors, and use more coloring next time? I used a spoon to put a spoonful of batter in at a time, so that the layers would stay intact and it wouldn’t make a mess in the jar. I’ve never tried using the bigger jars, because I was afraid of it not cooking all the way through in the middle. I’d be curious to know if anyone has had success with larger jars, too!?

  15. Anonymous says

    I read somewhere you can make carrot cake with baby food carrots. That would be cool to use them and still keep the wrapping on the jar. Sounds so good.

    • says

      Yes, I’m sure that would work, great idea! Then you won’t waste the food if you don’t have jars on hand. However, I wouldn’t keep the paper label on the jar to put in the oven, because it could start a fire in the oven if the paper starts to burn. You could also buy strawberry banana or a similar fruit flavored baby food and blend it in a smoothie with other fresh fruit, and I bet no one would know the difference! ;)

  16. Anonymous says

    Hi I absolutely love this idea I love baking and it’s my 12th bday in a months time, how long do I need to keep them in the oven and what temperature? Thank you ;p

  17. Anonymous says

    What kind of frosting did you use for this and if it was a homemade frosting could you please post the ingredients?.


Leave a Reply