Surprise Easter Egg Cake

Cake

1. Line 4 9" cake pans with parchment paper and spaying with baking spray. Preheat the over to 350°F.
2. Combine the cake mix, eggs, milk, water, vegetable oil, yogurt, and lemon juice in a large mixing bowl. Mix until all ingredients are well incorporated into a smooth batter.
3. Pour the batter evenly between the four prepared cake pans. Place in oven and bake for about 22 minutes, or until a toothpick inserted in the center comes out clean. Remove pans from the oven and place on racks to cool.
4. After the cakes have cooled completely, remove from the pans and cut a 3" - 4" circle out of the center of 2 of the cakes. Use a sharp knife with a parchment circle as a guide or use a large circle cookie cutter.
5. To assemble and frost the cake, take one cake without a hole in it and place it as the bottom layer on your cake stand and frost the top with white frosting.
6. Place one of the cakes with a hole in it and place it on top of the base layer, frost the top with white, then add the second cake with the hole in it and frost the top of it with white as well.
7. Fill the hole with mini robin eggs, sprinkles, and mini pastel baking chips then add the final cake to the top then frost the top and sides of all four layers with the remaining white frosting.
8. Once the entire cake is frosted in white, place dollops of about 2-3 teaspoons of alternating pastel colored frosting all over the sides of the cake.
9. Using an offset spatula or bench knife, smooth the frosting dollops around the sides of the cake in a marble-like pattern. Only smooth it enough to pull the color around. Don't smooth too much or the frosting will blend into one color.
10. Place any remaining colored frosting into a piping bag fitted with an open star tip and pipe stars around the top edge of the cake, top with Cadbury Mini Creme Eggs.

Frosting

1. To make the frosting, first cream the butter, vanilla, and salt together in a stand mixer until light and fluffy. Next slowly add the powdered sugar a little bit at a time until desired consistency.
2. Place 1 cup of frosting in each of three bowls. Add a drop or two of pink food coloring to one bowl, yellow to the second bowl and green to the third bowl. Mix until each color is uniform and the shade desired. Leave the remaining frosting white to use later.