Sift the cake flour, baking powder, baking soda, salt and skim milk powder into a bowl and mix together. In a separate bowl, combine the buttermilk and vanilla extract. Set both bowls aside.

In a large bowl, whip the butter and sugar together with an electric mixer until pale and fluffy. Then add the eggs and egg whites one at a time, mixing after each addition. Add the flour mixture to the egg mixture in 3 additions, alternating with the buttermilk mixture (flour>buttermilk>flour>buttermilk>flour), gently mixing after each addition. Divide the mixture into 2 bowls and dye one bowl pink. Divide the diced strawberries between the two bowls and mix until just combined.

Place dollops of both batters into a greased Hello Kitty cake pan. Bake at 350F for 1 hour or until fully cooked. Transfer the cake to a cooling rack and allow it to cool in the pan for about 10 minutes, then remove from the pan and place directly on the wire rack to cool completely.

Dye some buttercream pink, yellow and black and leave the remaining large amount of buttercream white. Place the buttercream into piping bags fitted with star-shaped piping tips and decorate the cake! Enjoy!