Get a clean bowl,put margarine and sugar and whisk in a medium speed for 10minutes.

Break eggs in it and whisk again this time for 5minutes,

In a separate clean bowl measure out flour and baking powder and sieve.divide it into two and pour in the mixture whisk on a medium speed for 5minutes.

Pour in the remaining flour and baking powder and whisk for 10minutes make sure is well folded in.

Divide the batter into two,add the vanilla in one and chocolate in the bigger one.

Pour in a baking pan,and bake for 45minutes.