Rainbow Road Chocolate Cake Recipe

When it comes to rainbow sprinkles, the Rainbow Road mix totally takes the cake. It’s become my absolute go-to for decorating all kinds of cakes and cupcakes, and it works well with any color of buttercream as a background. Just look at how it stands out on this chocolate buttercream:

The Rainbow Road sprinkle mix is essentially every vibrant color of the rainbow in a bottle. In addition to all that vibrance, this mix also comes with little white star sprinkles and metallic silver dragees to really make those sprinkles stand out. Since I’m so in love with all the beautiful shapes and colors going on in this mix, I decided to really let the sprinkles shine when it came to dressing up this chocolate cake recipe.

Let’s talk about this cake. It’s my go-to chocolate cake recipe for a few reasons: 1) it’s moist, decadent, and full of flavor, and 2) it’s a one-bowl cake recipe. Yes, you read that right. ONE bowl. That makes this chocolate cake recipe about as easy as whipping up a box of cake mix! You basically pour everything into your mixer (in the right order, of course) and blend it into the perfect cake batter in a matter of minutes.

I filled and frosted these chocolate cake layers with my favorite chocolate buttercream recipe, which is just as much of a go-to. It’s been described by a friend as “the type of frosting you have to put in the sink and fill the bowl with water to make sure you stop eating it.” Together, this chocolate cake and chocolate buttercream make the perfect pair, satisfying for any chocolate lover.

Decorating this beauty isn’t hard to do when you’ve got a bottle of Rainbow Road sprinkles on hand. I placed tons of sprinkles around the base of the cake, then added them one-by-one in a floating sprinkle technique to the top of the cake. It makes a pretty cool ombrè effect that way. You can use a pair of tweezers to add the single sprinkles, but I usually just press one on to my finger and gently press the sprinkle into the cake. After that, all that’s left to do is pipe a fun buttercream border on top (I used Wilton Tip 1M to create a rope border) and add even more sprinkles. And voila, it’s a stunner!

Rainbow Road Chocolate Cake Recipe

Ingredients

• 3 Cups (415g) all purpose flour
• 2 1/2 Cups (530g) white granulated sugar
• 1 Cup (95g) unsweetened natural cocoa powder (not Dutch Process)
• 1 Tbsp baking soda
• 1 1/2 tsp baking powder
• 3/4 tsp kosher salt
• 3/4 Cup (177ml) vegetable oil
• 3 eggs, room temperature
• 2 tsp vanilla extract
• 1 1/2 Cups (355ml) full-fat buttermilk*, room temperature (DIY recipe in the notes)
• 1 1/2 Cups (355ml) hot water

Instructions

1. Preheat the oven to 350ºF and prepare three 6-inch cake pans by spraying the sides with cooking spray and fitting the bottoms with a wax paper or parchment cake circle.
2. Place all of the dry ingredients into the bowl of a stand mixer and stir on low for 30 seconds to fully combine them. Add the vegetable oil, eggs, vanilla, and buttermilk and mix on low until just combined. With the mixer still on low, add the hot water in a slow stream, then turn the mixer to medium and beat until smooth, about 2 minutes. The batter will be very thin.
3. Pour into prepared cake pans no more than 2/3 full and bake for 40-45 minutes, until a wooden toothpick inserted comes out clean. Cool completely before frosting with chocolate buttercream or frosting of your choice, then decorate with Rainbow Road sprinkles.

Recipe Notes

DIY Buttermilk recipe: add 1 Tbsp of white vinegar for every cup of whole milk you’ll be using. For this recipe, add 1.5 Tbsp of white vinegar to a jar and top it with 1.5 Cups of whole milk. Stir and let sit for 15 minutes before using in the recipe.

Make ahead tips: this cake can be made ahead and stored at room temperature, covered tightly in plastic wrap, for up to two days. Alternatively, you can cover with plastic wrap and store in the freezer for up to two months before thawing to room temperature.

Sweet Wishes,