This is a very different cookie than anything you've ever had, but man, are they good!! PLEASE try them this year on your Christmas cookie trays, you won't be disappointed! Recipe came from Better Homes and Gardens Feb. 2002, from Camilla Saulsbury.
Heat oven to 350 degrees. In a bowl combine flour, cornmeal, sage, and baking powder. Set aside. In a large mixing bowl cream butter and add brown sugar, beat until combined. Beat in egg yolks, lemon zest and vanilla. Mix in the flour mixture. Shape dough into 3/4 inch balls, place 1 inch apart on ungreased baking sheets. Lightly press the tip of your thumb into the center of each ball. Fill the centers with about 1/4 teaspoons of the blackberry preserves. Bake 10 minutes or until the bottoms are lightly browned. Cool on cookie sheet for 1 minute and then transfer to rack to cool completely.