Buttercake trial version

still looking for the best cake for the rainbow cake that i'm going to make for my niece..after few rounds of discussion with my dear fren, she recommended buttercake..so i gave it a try...the cake is soft but a bit dry, after asking, i found out that i've actually over baked it..thanks god i have a fren who will be there to guide me always... luv luv...i added some cocoa powder to see if the taste is ok...ended up, nice taste but texture too dry ler...and the batter colour gone so DARK! OMG! better stick to plain buttercake with vanilla essence if i wanna do nice rainbow cake...

my darling Cindy gave me this link as reference: http://wendyinkk.blogspot.com/2012/05/mrs-ngsks-butter-cake-butter-cake-3.html

Ingredients:
115gm softened butter (salted)
2 eggs
25gm + 65gm sugar
100gm self raising flour, sifted
30ml milk
1/2 tsp vanilla essence


Method:
1. Preheat oven at 180C. Line the tin base and grease the wall.
2. Separate the eggs, and place the whites into mixing bowl. Beat egg whites until soft peaks, gradually add 25gm sugar and beat until stiff. Set aside.
3. Cream butter and 65gm sugar until pale and fluffy. Put in vanilla essence and and beat for a while. 
4. Put in egg yolks one by one and beat well after each addition.
5. Put in 1/2 the flour and mix on low speed until incorporated. Put in milk in 2 additions and mix until well incorporated. Mix in balance of flour.
6. Put 1/2 the egg whites in and mix on low speed. Pour the balance of egg whites in and fold gently.
7. Divide batter and mix in desired colour and mix well. Pour coloured batter into pan and level.
8. Bake for 18-20 minutes or till cooked. (I've actually over baked cos was multitasking, i think I've set bout 30 minutes, that's why ended with dry cake)