Divide the frosting in half. Cover and set aside 1 half.
Divide the other half into thirds. You will use each third to make the pink, blue, and purple frosting colors.
To mix the pink color, add the beetroot powder 1 teaspoon at a time until the desired color has been reached.
Blue color, add butterfly pea powder 1 teaspoon at a time until the desired color has been reached.
Purple color, add 1 teaspoon beetroot and 1 teaspoon butterfly pea, and until the desired color has been reached.
Divide the remaining white buttercream into thirds and set aside ⅓ of it for any touching up later on.
Once the cakes are fully cooled, use a cake or bread knife and slice off the dome center of the cakes making them flat on top.
Place the bottom layer on a flat surface such as a cake plate or cardboard round. Add a dollop of white frosting and evenly spread to a 1/2” thickness.
Flip the other cake upside down and place it on top of the filling.
Completely frost the two layers of cake with a thin layer of white buttercream frosting. You can freeze the cake for about 30 minutes at this stage. It will make the additional decorating a bit easier - but it isn’t necessary for the decorating process.
Add more buttercream frosting to thicken the layer and form the base of your cake.
Insert the cake topper in the center of the cake. Place the eyelashes on the front of the cake - center to the cake topper. I used tweezers for this.
To pipe the unicorn mane, add the three colored frostings to the piping bags and use decorative piping tips.
For the pink, and purple, I used the drop flower piping tip. For the blue, I used the small round tip.
Pipe in a large rounding motion, to create a large, round flower.
Slowly continue to pipe the frosting colors in the open spaces until they have been filled to your liking.
Continue to pipe floral dots flowing from the back of the topper down and swooping to one side as a mane would lay. Randomize the placement of the colors.
Chill until ready to serve.