In large bowl, cream butter, sugar and salt with electric mixer until light and fluffy. Add egg yolks one at a time, mixing well after each addition. Add vanilla. Add flour: mix just until combined. (Note: Dough can be tinted with Wilton Icing Color. Add small amounts until desired color is reached.) Divide dough in half. Press dough to flatten; wrap with plastic wrap. Refrigerate at least 2 hours or overnight.

Preheat oven to 375°F. Work with one dough disk at a time. Let chilled dough stand at room temperature for 10 minutes. Lightly flour work surface and roll dough 1/4 in. thick. Depress imprint disk into flour, then cut and imprint cookies. Gather scraps and roll dough again to make more cookies. For best results, depress disk into flour after each use. Carefully transfer cookies to an ungreased cookie sheet, leaving 1 in. between cookies. Bake 14-16 minutes or until edges are lightly browned. Remove cookies from cookie sheet and cool completely on cooling grid.