Preheat oven to 180C/350F/Gas 4 and spray 3 (9-inch) round cake pans with baking spray.

Make the cake batter according to the package instructions and divide the mixture equally between three bowls.

Add a few drops of pink food coloring gel into one bowl of cake mix and stir distribute the color and until the batter is the shade you want.

Add a few drops of yellow food coloring gel into the second bowl and stir to combine as before.

Add a few drops of teal food coloring gel into the third bowl of cake mix and stir combine as before.

Scoop about ¼ cup of the yellow cake batter one of the prepared cake pans. Add the same amount of teal cake batter and place it next to the yellow, and finally with the same amount of pink cake mix next to both. Repeat this again to fill the pan, then repeat the steps again in the other two cake pans. If you have any mixture left over, add colors where necessary.

Bake in the oven for 25-35 minutes or until a toothpick comes out clean when inserted in the middle.

Allow the cake to cool in the pan for 5 minutes before transferring to a wire rack to cool completely.

When the cakes are completed cooled, use a cake leveling tool (or sharp knife) to remove the dome from the cake.* This is so there is a flat top for layering the cake with frosting.

To make the frosting, using a stand mixer, combine the softened butter, powdered sugar, and cream and beat until smooth and stiff peaks form.

Scoop 1 cup of frosting into 3 bowls and color one each pink, yellow, and teal. Add to piping bags.

Color the remaining frosting with black food gel. Add ½ cup black frosting to a piping bag.

To assemble the cake, place the first layer on a cake board (I always dab some frosting in the center of the board to stick down the cake) and spread about 1 cup of frosting in an even layer. Place the second cake layer and spread another cup of frosting in an even layer. Place the third and final layer on top.

Using the remaining frosting, cover and smooth the entire cake. Place in the fridge for 2 hours to set/harden.

To decorate, cut the tips off the four piping bags and using the black, pipe the square/rectangles outlines of Sally's patchwork dress.

Using the pink, teal, yellow, and black frosting, fill in each of the squares or rectangles - try not to put the same color next to each other! Use a picture of Sally as a guide.

When all the sections are filled in, pipe the details with black - lines, dots, swirls, stitches, etc.

Place into the fridge again to allow the frosting to harden up before cutting into slices and serving.