Colorful Rainbow Cake Roll Recipe: How to Make a Vibrant Swiss Roll

This colorful rainbow cake roll, layered with sweet vanilla buttercream, starts from a white cake mix and makes a striking striped Swiss roll. Step-by-step photos guide you through piping the colored batter and rolling the cake for celebrations, birthdays, or St. Patrick’s Day.

Rainbow Desserts

Rainbow desserts bring instant joy. Their vibrant layers feel playful and nostalgic, and I often make one around St. Patrick’s Day. Past creations include rainbow cupcakes (two versions: colored cake mix and homemade funfetti with rainbow icing) and even rainbow bread, which makes fun French toast. This season I wanted to try a rainbow cake roll — a striped Swiss roll made from a doctored cake mix for an easier shortcut when creating multiple colors.

Striped Swiss Roll

I’ve made many cake rolls — pumpkin, carrot, and red velvet — but this was my first striped version. Inspired by other multi-colored rolls, I used a doctored box cake batter to simplify the process. Because you divide and color the batter several times, piping the stripes requires patience and some skill. It’s a great project for bakers who want a slightly more advanced, rewarding recipe.

How to Make a Rainbow Cake Roll

Below is a concise overview of the process. Detailed instructions and photos follow.

1. Make the cake batter by combining dairy, egg whites, oil, and the cake mix.
2. Divide the batter into six portions, tint each with gel food coloring, and fill piping bags.
3. Pipe diagonal rainbow stripes onto a parchment-lined half sheet pan.
4. Bake, then immediately roll the warm cake in the parchment to set its shape.
5. Once cooled, unroll, spread vanilla buttercream, and re-roll with the filling inside.
6. Wrap and chill the roll to firm it before slicing.
7. Slice into 3/4-inch pieces and serve.

Note: A cake roll made from boxed mix is a bit more delicate than some homemade sponge rolls. Follow timing and handling tips to minimize cracking.

Step 1: Make the Cake Batter

Preheat the oven to 325°F. Line a 13×18-inch half sheet pan with parchment, leaving a couple inches of overhang to lift the cake out easily. In a large bowl whisk together sour cream, buttermilk, vanilla, egg whites, and oil until well combined. Sift the white cake mix into the wet ingredients and stir just until combined — do not over-mix.

Step 2: Divide, Color, and Bag the Batter

• Divide the batter into six small bowls (about 2/3 cup in each). Tint each portion with gel food coloring — red, orange, yellow, green, blue, and purple work well.
• Fill disposable piping bags with each colored batter. Cuffing the bag over a glass rim makes filling easier. Twist the top of each bag and leave the tips uncut until you’re ready to pipe.

Step 3: Pipe Stripes in Rainbow Order

• Optionally spray the parchment with a nonstick spray containing flour for extra release. Cut the tips of the piping bags and pipe diagonal stripes across the pan in rainbow order: red, orange, yellow, green, blue, purple.
• Pipe thin at first so you can go back and fill gaps rather than risk running out of batter. Tap the baking sheet on the counter to remove air bubbles and help the stripes settle together.

Step 4: Bake and Roll the Cake

• Bake at 325°F for about 17 minutes, until set.
• Immediately lift the cake from the pan using the parchment and place it on a wire rack. Let steam escape for 4 minutes, then roll the warm cake up from a short side in the parchment to set the shape. Cooling this way prevents major cracks.
• Let the rolled cake cool completely (about 40 minutes) while you prepare the vanilla buttercream.

Step 5: Unroll and Fill with Frosting

• Carefully unroll the cooled cake. If condensation has caused any sticking, use a spatula to gently loosen crumbs from the parchment.
• Spoon the vanilla buttercream along the cake and use an offset spatula to smooth it, leaving a 1/2-inch border at the far edge so filling doesn’t spill out when re-rolling.

Step 6: Re-roll with Filling Inside

• Roll the cake tightly, using your fingers to start and lifting the parchment to continue rolling without compressing the cake. Pull the cake away from the paper as needed to avoid sticking.

Step 7: Wrap and Chill

• Wrap the roll tightly in plastic wrap and freeze for 1 hour or until firm (or freeze overnight). Leaving the cake on its parchment while trimming the excess makes it easier to transfer to plastic and reduces cracking.

Step 8: Slice and Serve

• Unwrap the chilled roll and slice with a hot knife into 3/4-inch pieces (about 16 slices). Rinse and dry the knife between cuts for clean edges. Slices thaw in roughly 15 minutes at room temperature.

Important Tips

• Roll while the cake is still warm. Let most steam escape (about 4 minutes), then roll to reduce cracking. Timing is key.
• If this is your first cake roll, consider using a powdered sugar-dusted tea towel instead of parchment to help the cake release and allow steam to escape. Boxed mixes can stick more to parchment than some homemade sponges.

If you try this recipe, please rate and leave a review in the comments — thanks!