I'm a newbie to this group, but cookies, and healthier cookies are a
huge quest of mine as well. I've always loved cookies. They are, in
my opinion, the perfect snack and treat. Anyway, I best not get
started on my love of cookies too much, it would take far too long to
go into it. Baking Powder and Baking Soda are leaveners. When they
are mixed with liquids (and sometimes heat) they bubble and fizz,
therefore "raising" whatever they're used in. I use whole wheat in
everything anymore. I've used 1/2 to 1/3 in most drop cookies. The
thing I can say about using it, is that whole wheat usually takes up
more liquid. So you have to watch the consistency of your dough when
experimenting. For the Chocolate Chip Cookie recipe I use, the
cookies come out best when the final dough is slightly crumbly, but
not dry. Then when you bake them, bake just until very lightly
browned and slightly under-done in the center; then let them sit on
the cookie sheet for a few minutes before removing to a rack to cool.
This will give you a soft chewy cookie. For thin crisp cookies, use a
wetter dough. Anyway, just a couple of thoughts