In a medium bowl, whisk together flour, baking powder and salt until well combined.
Cream together butter, sugar, and shortening until light and fluffy.
Add egg whites one at a time, mixing well between each addition.
Add the vanilla and almond extracts and mix well.
On low speed alternate adding the flour mixture and the milk to the butter mixture, beginning and ending with the flour mixture.
Pour the batter into the prepared pans and bake the 6-inch cake for 45 minutes, and the 10-inch cake for 1 hour.
Time to decorate!
Trim the tops of the cakes using a cake leveler and then cut each cake horizontally into 2 layers. Assemble on a cake board, spreading frosting between each layer (PICTURE at 7:30).
Cover the cakes with a crumb coat layer of frosting and then refrigerate for 30 minutes.
Roll out light blue fondant about ¼ inch thick and then cover the 6-inch cake (PICTURE at 8:52). Use a knife to remove any excess.
Roll out green fondant to ¼ inch thick and then cover the 10-inch cake (PICTURE at 9:16). Cover a 10-inch cake board in green fondant.
Place the 10-inch cake on the cake board. Use large straws as support to stack the 6-inch cake on top of the 10-inch cake.
Use colored fondant to create a rainbow, trees, bushes, apples, clouds, and cutie marks (PICTURE at 3:36).
Place fondant pieces and pony figurines on the cake to create a scene (PICTURE at 10:09).
TaDa! Friendship is magic, and so is this My Little Pony Cake!