The layers of this Rainbow Jello Cake will add a colorful pop and jiggle to any table! To get all the colors of the rainbow, you use almost every jello flavor and as a result, the cake tastes like fruit punch! Not only do the white layers of condensed milk contrast against the jello layers, but they add sweetness and a little creaminess to the dessert.
While this recipe does have a long timeframe, the majority of it is spent waiting for each layer to set. Don't let the lengthy preparation deter you, the techniques involved and process are so easy to do!
I made this cake in celebration of Pride Month, and it would also be great to serve for birthday parties or St. Patricks day!
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Ingredients
- Jello Colors: to get a layer with each color of the rainbow, you'll need six different flavors of jello. I'd recommend using grape for purple, berry blue for blue, lime for green, lemon for yellow, orange, and strawberry or cherry for red (I use strawberry!)
- Unflavored gelatin: the gelatin will help make the layers of jello and sweetened condensed milk more firm.
- Sweetened condensed milk: layers of sweetened condensed milk separate the layers of jello to define each layer as well as add a little creaminess and sweetness.
- Boiling water
Please see the full list of ingredients and measurements at the bottom of the post.
Instructions
This recipe is as easy as wash, rinse, and repeat! You alternate between making layers of jello and layers of condensed milk, letting each one set in the refrigerator.
Starting from the bottom, the order of the layers should go: purple (grape flavor), white (condensed milk layer), blue (blue berry), white, green (lime), white, yellow (lemon), white, orange, white, red (strawberry).
To begin, lightly spray your cake pan with cooking spray.
Then, to make the first layer, mix together the grape jello packet with gelatin and boiling water. Make sure to always mix until everything is dissolved and is a smooth, cohesive liquid. The first layer is the bottom layer, so make sure you start with purple, not red!
Mix together the grape jello with gelation and boiling hot water. Pour into a lightly greased 9 x 13 pan and chill in the refrigerator.
While the jello is setting, make half of the condensed milk mixture.
After the grape layer has set, pour ¾ cup of the condensed milk mixture on top of it. Let this set in the fridge for another 20 - 30 minutes.
Repeat with the remaining flavors and colors.
A Few Helpful Tips
- Make sure to place the baking dish on an even surface inside your fridge. If the dish is slanted in any direction, the layer will also set as slanted!
- Mix the condensed milk, gelatin and water in a measuring cup so that it's easily pourable and you can measure how much you pour out at the same time. Keep the measuring cup covered with plastic wrap in between use.
- Use a clean bowl for each flavor of jello. You don't want some of a leftover color to mix into your current one!
- Don't pour your jello or condensed milk in just one spot when adding them to the cake. Pour evenly across the previous layer, otherwise, you may end up drilling a hole into it!
- Let each mix come to room temperature before pouring it. I like to prepare either the jello or condensed milk for the next layer after placing the cake in the fridge. That way it can cool down as it sits on the counter.
What Kind of Pan to Use
Use a 9 x 13 baking pan to make this cake; preferably, one with straight edges. Using a straight-edged pan will give you the cleanest cake slices, with even, straight edges on all sides of each slice.
If you use a baking pan with curved sides, you can trim the edges to get straight cake slices, or just serve them as is! It'll be yummy any way you slice it!
Rainbow Jello Jigglers
Instead of serving this as a cake, slice the jello into small rectangles to make rainbow jello jigglers! You can get about 24 jigglers out of this rainbow jello cake!
You can make jello jigglers about 7 to 10 days ahead of time! Make the layered jello and then cover the dish with plastic wrap once everything is set. Keep it in the fridge until you're ready to serve them!
Storage
Keep your jello cake stored in the refrigerator, wrapped in plastic wrap. It should last about 7 to 10 days properly stored in the fridge.
Rainbow Jello Cake
Ingredients
- 6 packages of 3 oz jello in assorted flavors suggested: grape, berry blue, lime, lemon, orange and strawberry
- 12 teaspoon unflavored gelatin
- 14 ounce can sweetened condensed milk
- 8 cups boiling water divided
Instructions
- Lightly spray a 9 x 13 pan with non-stick spray and set aside.
- In a small mixing bowl, mix the package of grape jello with 1 teaspoon of gelatin and 1 cup of boiling water. Whisk until completely dissolved.
- Pour the mixture into the 9 x 13 pan. Then, place the dish in the refrigerator until the jello sets, about 20-30 minutes. Make sure to place it on an even surface so that you get even layers.
- While the first jello layer is setting, make the mixture for the layers of condense milk. Start by adding 2 teaspoons of gelatin to 1 cup of boiling water and whisk until it's dissolved.
- Add ½ can of condensed milk (just over ¾ cups) and mix to combine. Let the condensed milk mixture sit on the counter to cool while the purple jello layer is setting in the fridge.
- Once the jello is set and the condensed milk mixture has cooled, pour ¾ cup over the condensed milk mix over the layer of grape jello. Return the dish to the refrigerator to set for another 20 minutes. Cover the remainder of the condensed milk mixture with plastic wrap while it’s not in use and leave on the counter.
- Prepare the next layer of jello (the blue berry) by mixing the package of jello, 1 teaspoon of gelatin, and 1 cup of boiling water and whisking until dissolved. Let this sit on the counter while the layer of condensed milk is setting in the fridge.
- Repeat this process alternating between layers of jello and the condensed milk mixture, which you'll need to make the rest of half way through.
- The layers should go from bottom to top in this order: grape, condensed milk mixture, blue berry, condensed milk mixture, lime, condensed milk mixture, lemon, condensed milk mixture, orange, condensed milk mixture, strawberry.
- Serve with whipped cream and rainbow sprinkles!
Notes
- I like to fill up a pot with about 8 ½ cups of water and leave it on the stove to boil whenever it’s time to create a new layer of jello. I add the extra ½ cup because some of it will likely burn off as steam in the process. You can of course boil a cup of water one cup at a time as the instructions call for it!
- I suggest making the condensed milk mixture in two stages because it will begin to set as time goes on.
- Mix the condensed milk, gelatin, and water in a measuring cup so that it's easily pourable and you can measure how much you pour out at the same time. Keep the measuring cup covered with plastic wrap in between use.
- Use a clean bowl for each flavor of jello. You don't want some of a leftover color to mix into your current one!
- Don't pour your jello or condensed milk in just one spot when adding them to the cake. Pour evenly across the previous layer, otherwise, you may end up drilling a hole into it!
- Let each mix come to room temperature before pouring it. I like to prepare either the jello or condensed milk for the next layer after placing the cake in the fridge. That way it can cool down as it sits on the counter.
Nutrition
Please note, Holiday Sweets N Treats isn't a professional nutritionist. Any and all nutritional information shared is an estimate. If you're following a specific diet or counting calories, we suggest you use the nutrition calculator of your choice. Calories can vary depending on the brands and products used.
Courtney
The instructions were so clear!! Easy recipe to follow and it turned out amazing
Emma
Thank you! I’m so glad you enjoyed it!