About the Recipe
I’ve always loved Bundt cakes for their simplicity—you don’t need fancy decorating skills to make one look beautiful. The pan does the work, and the result always feels a little bit special. For this Rainbow Bundt, I wanted to play with color inside the cake, similar to how I had fun with the bold color in my Red Velvet Cupcakes or the party magic of my Rainbow Popcorn. I used the lemon base from my Lemon Pistachio Bundt Cake—because lemon just pairs so well with everything—and swirled in natural dyes to create a rainbow marbled effect.
The powders—purple sweet potato, butterfly pea flower, beetroot, and cranberry juice—add beautiful, earthy tones. The flavors are soft and subtle (except the cranberry, which has a nice little zing that works well with the lemon). I tested it a few times to get the colors right—beetroot especially loves to fade in the oven—but blending it with cranberry helped keep some of that pinky red.
If you’re looking for a fun, naturally colorful cake that’s as joyful to cut into as it is to eat, this Bundt might be just the thing.
Vibrant Colors from Natural Ingredients: Made with natural dyes from ingredients like turmeric, beetroot, and spirulina, this cake is a stunning rainbow creation with no artificial colors.
Deliciously Moist and Flavorful: This bundt cake is as tasty as it is beautiful, with a moist crumb and a light, vanilla or citrus flavor that pairs well with the natural hues.
Fun and Wholesome: Perfect for celebrations, this cake offers a fun, healthier way to enjoy rainbow colors, making it ideal for kids’ parties or special occasions.
Impressive Presentation: The bright layers and bundt shape make this cake a showstopper, bringing a burst of color and joy to any dessert table.
Easy to Adapt with Favorite Flavors: Add a touch of lemon zest or vanilla extract to the batter, or drizzle with a simple glaze for extra flavor without overpowering the natural colors.
Perfect for Natural-Living Enthusiasts: For those who avoid artificial colors, this cake offers a vibrant and healthy way to enjoy a colorful dessert that’s free from synthetic additives.
What You'll Love
What types of natural dyes work best for a rainbow bundt cake? Plant-based powders, like beetroot, turmeric, and spirulina, are ideal for vibrant colors. For best results, use fine powders from sources like Selefina to ensure even coloring.
Will the natural dyes affect the cake's flavor? Most natural dyes have subtle flavors, but they typically blend well with cake batter. For a more neutral taste, adjust the quantity slightly or pair with flavors like vanilla or citrus.
Can I make the cake layers without artificial colors? Absolutely! This recipe uses only natural dyes, providing beautiful colors without any synthetic ingredients, perfect for those who prefer natural alternatives.
How should I store the rainbow bundt cake? Keep the cake in an airtight container at room temperature for up to 3 days or in the refrigerator if you prefer it slightly chilled. The colors stay vibrant and fresh for several days.
Can I freeze leftover rainbow bundt cake? Yes! Slice the cake and wrap each piece in plastic wrap before freezing. Let it thaw at room temperature when you’re ready to enjoy a colorful, natural treat.
Frequently asked Questions
Ingredients
Cake
375 g all-purpose flour (3 cups)
12 g baking powder (1 tbsp)
3 g baking soda (½ tsp)
3 g salt (½ tsp)
227 g unsalted butter, softened (1 cup)
400 g granulated sugar (2 cups)
4 large eggs
5 g vanilla extract (1 tsp)
240 g buttermilk (1 cup) – see blog for DIY tip
Zest of 2 lemons
30 g fresh lemon juice (2 tbsp)
Natural Coloring Powders
*Use a few drops of food coloring if you do not have natural powders
6 g purple sweet potato powder (2 tsp)
6 g butterfly pea powder (2 tsp)
6 g beetroot powder (2 tsp)
6 g cranberry juice powder (2 tsp)
Optional: powdered sugar for dusting
Preparation
Preheat your oven to 350°F (175°C). Grease and flour a 10-inch Bundt pan.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
In a large mixing bowl, cream together the butter and sugar until light and fluffy.
Beat in the eggs, one at a time, then stir in the vanilla extract.
Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk, beginning and ending with the dry ingredients. Mix until just combined.
Stir in the lemon zest and lemon juice until well incorporated.
Divide the batter into 4 small bowls. Add the coloring type of your choice to each bowl. I put the beetroot and cranberry powders into the same bowl, the butterfly pea into its own and the purple sweet potato into its own as well. The last bowl of batter will be left as is. Mix the powders into each bowl until the dyes are well incorporated.
Alternate pouring in the colored batters into the prepared Bundt pan and use a knife or cooking skewer to zig-zag through the batter to create a marble effect. Smooth the top with a spatula.
Bake in the preheated oven for 45-55 minutes, or until a toothpick inserted into the center comes out clean.
Allow the cake to cool in the pan for 10 minutes, then invert it onto a wire rack to cool completely.
Once the cake has cooled, dust with powdered sugar.
Slice, serve, and enjoy your delicious Rainbow Bundt cake!
Tips
If you don't have buttermilk on hand, you can easily make a substitute using milk and lemon juice or vinegar:
Measure out 1 cup of milk (whole milk or 2% milk works best).
Stir in 1 tablespoon of lemon juice or white vinegar.
Let the mixture sit for about 5-10 minutes to allow it to curdle and thicken slightly.
After it has thickened slightly and looks somewhat curdled, it's ready to use as a substitute for buttermilk in your recipe.