- 1 cup unsalted butter, room temp
- 2 cups granulated sugar
- 5 large egg whites, room temp, lightly whisked
- 1 1/2 teaspoon vanilla paste
- 1/2 cup sour cream, room temp
- 3 cups all-purpose flour
- 1 Tablespoon baking powder
- 1 teaspoon baking soda
- 1/2 teaspoon fine sea salt
- 1 cup whole milk
- soft gel paste food colors*super red, lemon yellow, electric orange, electric green, electric blue, and royal purple
- Preheat oven to 350 degrees F. Gather as many 9” round cake pans as you can find. I only had two, so I had to clean the pans between baking. Butter and line the cake rounds with parchment paper rounds. Set aside.
- In a bowl of a stand mixer with the paddle attachment, cream butter. Add sugar and continue to cream until lighter in color. Slowly add egg whites to the butter on low-medium speed. Add vanilla paste and sour cream. Mix until thoroughly combined.
- In a medium bowl, whisk together flour, baking powder, baking soda and salt.
- Alternate adding flour mixture and milk to the creamed mixture. Add the flour in three additions, beginning and ending with the flour.
- If you have a kitchen scale, transfer the batter to another bowl and weight it out. Take the weight and divide it by 6. My total weight was 1530 grams. Divide by 6, it was 255 grams. Measure of 255 grams of batter into 6 small bowls. If you don’t have a scale, it was roughly 3/4 cup of batter into 6 bowls.
- Add food coloring to individual bowls. I used about 4-8 drops of coloring for each. Some colors required more gel than others to get the vibrant hues I wanted. Be sure to use food gels. Adding liquid food coloring will make your batter too runny and thin.
- Transfer colored batter to prepared cake pan. Bake for 13-15 minutes until cake is set. Let cool in pan for 3 minutes before unmolding and allowing to cool completely on the racks. Continue to bake off cakes until you have completed all six colors