Preheat oven to 350 degrees F. Line the bottom of two 8-inch round cake pans with parchment paper and grease well. Set aside.

In a large bowl, combine 1 box of cake mix with 1 1/4 cups water, 3 whole eggs, and 1/3 cup of vegetable oil. Use a hand mixer to blend ingredients for 2 minutes. Divide batter evenly between two prepared pans.

Bake cake layers for 29-34 minutes until a toothpick inserted into the center comes out clean.

Allow cakes to cool for 10 minutes in the pan then remove to a sheet of waxed paper to cool completely.

Repeat steps 1-4 for the two additional boxes of cake mix. You should have a total of 6 cake layers when done. Allow cake to cool completely.

Level cake layers using a serrated knife.

Make vanilla buttercream frosting according to directions. Add several drops of sky blue food coloring until you get the desired shade. Mix well.

Stack up 5 of the 6 cake layers, adding a layer of sky blue frosting between each one. Wrap the Snow White doll with plastic wrap up to her waist then press it into the middle of the cake layers. The cake should come up slightly below the doll's waist. If it doesn't, remove the doll and add the 6th cake layer then reinsert the doll. Place the cake into the refrigerator to chill for at least 30 minutes.

Remove the cake from the refrigerator. Starting at the top of the cake, use a serrated knife in a sawing motion to carve the cake into a bell shape. Work toward getting the general shape then you can refine it further from there.

Add a crumb coat by using a knife or offset spatula to spread a thin layer of blue frosting all over the sides and top of the cake. Return the cake to the refrigerator to chill for at least 30 minutes.

Add the remaining blue frosting to a piping bag that has been fitted with an open star tip, such as the Wilton 1M tip. Secure with a clip.

Remove the cake from the refrigerator. Starting at the bottom of the cake, pipe rosettes all the way around the bottom then work your way up the cake. The rosettes should be touching. If there are any gaps, you can fill them by piping stars between the rosettes. As you get to the top of the cake, pipe the rosettes right up to the doll's waist, making sure you completely cover the plastic wrap.