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Rainbow St. Patrick's Day Cake

Rainbow St. Patrick’s Day Cake is super easy to make & the perfect dessert for your St. Patrick’s Day celebrations! Plus it’s topped with MARSHMALLOWS!
Course Dessert
Cuisine American
Keyword cake, rainbow, st patrick's day
Prep Time 20 minutes
Cook Time 30 minutes
Total Time 50 minutes
Servings 12
Author Gina Kleinworth


  • 1 white cake mix - plus ingredients per the box instructions- oil, water, eggs)
  • Food Color red, orange, yellow, green, blue & purple
  • 1 can pre-packaged frosting or homemade if you prefer
  • Lucky Charm marshmallows - just the marshmallows not the cereal
  • rainbow sprinkles


  • Preheat the oven according to the box mix directions.
  • Spray a 9x13 metal baking pan with cooking spray - set aside.
  • In a mixer bowl, combine the box mix ingredients & beat until combined.
  • Ladle out equal portions of the batter into 6 separate bowls.
  • Mix in several drops of food color - one for each bowl so you have a rainbow of batter.
  • Carefully drizzle batter into the prepared pan. I started with red & spread it out to cover the bottom of the pan. Then follow with orange - drizzling in a random pattern - do not stir or mix - just let them sit on top of each other. Follow with the remaining colors - yellow, green, blue, purple.
  • Bake according to the package instructions - remove & cool completely before adding the frosting.
  • Once cool, spread on the frosting, add the marshmallows & sprinkles.