FOR DOUGH: In a large bowl of an electric mixer, beat butter, granulated sugar and brown sugar until creamy. Beat in eggs and vanilla. In another bowl, stir together the whole wheat flour, allpurpose flour, wheat germ, salt and baking soda; gradually add to butter mixture, blending thoroughly. Cover dough tightly with plastic wrap and refrigerate until easy to handle (at least 1 hour) or until the next day. Meanwhile, prepare filling of your choice; set aside.