Whole wheat PASTRY flour is key here. If you use regular whole wheat flour, your cookies will be dense. The pastry flour gives them the texture that all purpose flour would. I use Bobs Red Mill Organic Whole Wheat Pastry, available at most grocery stores.
Your dough will seem very sticky when forming it into balls (having damp hands help it not stick to your fingers!) this is due to the extra eggs. It is totally how it should be, and will keep these cookies so soft!