Rainbow Cake in a Jar | Family Kitchen

I’ve always had a penchant for sunshine in a jar. Doesn’t the very phrase itself, “sunshine in a jar,” roll off your tongue and fill your mouth with magic? While I’ve never yet found myself a sunshine in a jar, I think we may have just concocted it in our kitchen tonight. In this simple recipe, a basic white cake is turned into a slew of bright colors, baked to perfection, then topped with a creamy white frosting.
Cakes baked in jars can be topped with traditional metal canning lids and stored in the fridge for up to five days. They make a great treat to ship to someone, so long as you can ensure delivery to it’s final destination within 3 days. Of course, you don’t have to do anything special with your cake-in-a-jar. There’s something lively & different about serving personal-sized batched of cake in glass mason jars. They make for great dinner party conversations and ever better after-school suprises for your kiddos. Especially this one. Because, who doesn’t love sunshine in a jar?

Rainbow Cake in Jar

• 1 box white cake mix made according to package instructions
• Neon food coloring in pink, yellow, green, turquoise, and purple
• 3 one-pint canning jars
• 1 can vanilla frosting
• Rainbow sprinkles

Preheat oven to 350 degrees. Thoroughly wash and dry the inside of each canning jar. Spray the inside of each jar thoroughly with nonstick cooking spray. Set aside.
Scoop about 1/2 cups of cake batter into five small bowls. It doesn’t have to be perfect, don’t panic if you get a little more of less of one color than another. Tint each bowl of cake batter with the food coloring until very vibrant.
Spoon about 3 tablespoons of the purple batter into the bottom of each jar. Spoon equal amounts of turquoise batter, then green, yellow, and pink. Place the jars in a shallow baking dish, add about 1/4″ in water in the baking dish. Place the baking dish in the oven and bake for 30-35 minutes.
Remove jars and allow to cool completely before scooping a small portion from the top of your cake and adding a hefty dollop of vanilla buttercream to the top. Sprinkle & serve, or cover with a lid and store in the fridge or pop into the mail & surprise someone you love!
POST EDIT: Several commenters have indicated that the cake is not cooking all the way through in the 30-35 minutes indicated in the recipe. This was enough time for our cake, but I’m cooking at high altitudes, and my oven tends to bake hot. So, I’d recommend baking the cake for 40 minutes, then return it to the oven if it still doesn’t spring back to the touch when you check to see if it’s finished. As for the cake puffing up and out of it’s bottle, ours did that a bit, as well. Easy fix. We just scooped a bit of the cake out to make room for the frosting and wiped the outside of our jars clean. Several people have indicated that the wide-mouthed mason jars work a little better for this purpose. I’ve not yet baked with wide-mouthed. What you see above is what was baked in my kitchen according to the recipe instructions, and what came out of the oven when it was all. Of course, if you’re feeling wildly impatient, you can also zap the cake in the microwave for 2 minutes. It’s going to bubble up, for sure, but you can scoop the top part of that cake out, frost it, and no one will ever be the wiser. Good luck, everyone! This is such a fun cake. My kids went nuts over it, and I hope it works as beautifully for you as it did for us!

Posted by brooke mclay on April 8th, 2011 at 12:08 am

Rainbow Cake in a Jar | Family Kitchen