I always use Colette Peter's white cake recipe and would love to turn it into a yellow cake (love the texture & flavor). Can I switch the 8 egg whites for 4 eggs and increase the baking powder to make this work? Thanks!

1.5C all-purp flour
1.5C cake flour
1C brown sugar
1C white sugar
8 egg whites
2 sticks butter
1.5C milk
2t vanilla
2t bkg powder
1t salt

I have used 3 whole eggs inplace of 4 egg whites in a reciepe, and it turned out great. So I'm thinking you would use 6 whole eggs.

Yep. Only difference between a yellow cake and a white cake is the eggs. I would use 4 whole eggs. I don't know about increasing the baking powder, though.