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Some desserts make people stop and stare, and this rainbow poke cake is absolutely one of them. Every slice reveals bold stripes of color soaked straight into a fluffy white cake, topped with a cloud of whipped cream. It looks like you spent hours on it, but you didn’t.

A slice of colorful, sprinkle-topped cake with white frosting sits on a plate next to a baking pan holding the rest of the cake.

I first made this for a summer cookout because I needed something that looked impressive but required little effort on my part. Complicated desserts are just not my thing. If a recipe asks me to temper chocolate or fold anything more than three times, I’m out. This one requires me to poke holes in a cake with a wooden spoon, and sometimes that’s exactly the right speed.

I love that the poke method does all the work. You bake the cake, poke holes across the top, and pour liquid Jell-O right in. As it sits, those colors sink deep into every bite. The result is soft, sweet, and perfect cold from the fridge with that cream on top.

It’s the kind of cake that fits anywhere. Bring it to a St. Patrick’s Day party and tell everyone the rainbow leads to dessert. Pack it for a summer picnic and watch it disappear in ten minutes. Or make it in June when the world is feeling extra rainbow-y and celebratory. This cake doesn’t need a reason. It just needs a crowd.

In this post, I’ll walk you through the foolproof steps to create this show-stopping dessert and share my best tips. If you can boil water and poke holes in a cake, you’ve got this handled.

Want more rainbow themed desserts? Try my rainbow Rice Krispie treats, tie dye Jello cookies, or Oreo snowcone balls.

Ingredient Notes

For exact amounts needed see the recipe card below

Cake mix: I like to use Funfetti cake mix for this recipe, but a white or yellow cake mix works too.
Ingredients to make the cake: Usually eggs, oil, and water.
Jello powder: You’ll need five different colors: red, green, yellow, blue, and purple. The small 3-ounce boxes are perfect for this.
Boiling and cold water
Frozen whipped topping: Cool Whip is the classic choice here. Make sure it’s completely thawed.
Rainbow sprinkles

Box of Funfetti cake mix, Jello powders in various flavors, frozen whipped topping, and rainbow sprinkles arranged on a counter.

How to Make Rainbow Poke Cake

Bake the cake according to the package instructions in a 9×13-inch baking dish and allow it to cool completely.
Use a wooden skewer or the end of a wooden spoon to poke holes all over the cake.
Place each color of the Jello mix in separate bowls. Add ¼ cup hot water to each bowl, stirring until the gelatin dissolves. Then, stir in ¼ cup cold water and continue mixing until well combined.
Use a syringe or carefully spoon each color of Jello over the cake, alternating the spots you pour the liquid to create a rainbow effect. Work slowly so the Jello has time to seep down into those holes you poked.
Cover your pan with plastic wrap and stick it in the fridge. I usually make this the night before I need it because four hours is the minimum, but overnight is even better. The Jello needs time to fully set inside all those little pockets.
When ready to serve, spread the whipped topping over the cake and decorate with rainbow sprinkles.

A pan of yellow cake with holes poked in the surface sits behind a small bowl of red liquid on a yellow checked cloth. — Dissolve all the Jello mixture.

A pan of baked cake with holes poked in the surface sits behind a small bowl filled with blue liquid, on a yellow and white checkered cloth. — Spoon each color of Jello over the cake.

Serving Ideas

If you’re bringing this rainbow poke cake to a potluck or celebration, I’d suggest serving it directly from the baking dish. It’s way easier to portion out for a crowd.

If you want to get fancy, transfer individual squares to dessert plates. You can serve it chilled straight from the fridge or let it sit out for 15 minutes if you prefer it slightly less cold. Either way works beautifully.

How to Store

Once you’ve cut into the cake, cover the pan tightly with plastic wrap or transfer any leftover pieces to an airtight container. The cake stays moist and delicious for up to 3 days in the fridge.

Don’t leave it sitting out at room temperature for more than 2 hours. Since this cake has whipped topping and Jello, both of which contain moisture, it can get a bit soggy if left unrefrigerated for too long.

A square slice of rainbow cake with white frosting and colorful sprinkles sits on stacked white plates beside a larger cake in a black pan.

Tips & Tricks

Be sure to check out the step by step instructions

Space your holes about an inch apart across the entire surface of the cake. You want enough holes for the Jello to seep through, but not so many that your cake falls apart.
Cool the cake completely before adding the Jello. A hot cake will absorb the Jello too quickly, and you’ll lose that gorgeous rainbow effect. Let it cool to room temperature, or even pop it in the fridge for 20 minutes if you’re impatient like me.
While you can use a spoon to add the Jello, a kitchen syringe or turkey baster gives you way more control over where each color goes. You can target specific areas and really create those distinct rainbow stripes.
Don’t rush when you’re adding the Jello mixtures. For a little while, wait a few seconds for it to absorb, then move to the next color.
The recipe says chill for four hours minimum, but overnight is even better.
Keep that whipped topping in the fridge until you’re ready to serve. If you want to frost it earlier, use regular frosting, not whipped topping.
Use whatever Jello flavors you have on hand or match them to your party theme. You can use as few as two colors or as many as six; divide your water accordingly.

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A slice of rainbow-colored cake topped with white frosting and multicolored sprinkles on a white plate.

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