Preheat oven to 300-degrees F. In a medium bowl combine flour, baking soda, lemon zest coriander and poppyseeds. Mix well with a wire whisk and set aside. In a large bowl cream butter and sugar with electric mixer at medium speed until mixture forms a grainy paste. Scrape down sidw of bowl, then add yolks, egg and lemon extract. Beat at medium speed until light and fluffy. Add the flour mixture and mix at low speed just until combined. Do not overmix. Drop by rounded tablespoons onto ungreased cookie sheets, 5 cm apart. Bake for 23-25* minutes until cookies are slightly brown along edges. Immediately transfer cookies with a spatula to a cool surface. *Note: Watch your time carefully on these cookies. Some of her various cookie recipes are done perfectly at the time she states, but others are crispy with all the chewiness baked out of them at the time she gives.