In a large mixing bowl with the mixer running, cream together the brown sugar and butter. Slowly add the egg, egg yolk and vanilla and lemon zest.

In another large bowl, sift together the flour and salt. With the mixer running, slowly add the flour mixture to the creamed mixture until thoroughly blended.

Chill the dough in the refrigerator overnight. Place a sheet of waxed paper on the counter. Put a portion of the dough on top of the waxed paper. Place another sheet of waxed paper on top of the dough and roll it out to a thickness of ¼". Cut the dough into small, 1 ½" rounds. Place the cookies on the baking sheet. Brush the top of each cookie with egg white and sprinkle some of the almonds on top.

Bake the cookies for about 8 minutes, just until the cookies are set and the edges lightly browned. Cool on racks.