Marble Cakes

0 Preheat oven at 350º.
1 In the bowl of your Kitchen Aid equipped with the whisk attachment, whip the butter until creamy. Add the sugar slowly and incorporate well. Add egg yolks one at the time.
2 With the motor running at slow speed, add the flour and then the milk. Add baking powder.
3 Beat the egg whites to soft peaks and incorporate them slowly to the flour mixture. Divide the creamy mixture into two bowls and add dark powder chocolate to one of the bowls. Mix well.
4 Butter the individual bundt cakes and sprinkle flour to coat them. Discard the excess.
5 Alternate dropping one tablespoon of cream mix and one tablespoon of chocolate mix until it reaches 3/4 of the way up the mold. With a toothpick, swirl the two batters together ever so gently.
6 Bake in the oven for about 30 minutes, then do the toothpick test: insert a toothpick into the middle; it should come out clean.
7 Remove from teh oven, wait to cool off 5 minutes then unmoild and place your cakes over a rack to completely cool off.