We wish we could share a treat with you in person, but since we can't here is a recipe you can make at home.
Cream together sugar, butter, vanilla and egg yoke. Stir in flour until dough sticks together and is uniform.
Roll dough into one-inch balls.
Lightly beat egg white.
Dip balls of dough into egg whites and then nuts (optional). Place on baking sheet.
Press a deep indent into the center of each cookie with a thumb, a thimble or a cork. If dough is very soft, refrigerate before baking.
Bake cookies 10 minutes at 350 degrees, or until light brown. Cool for 30 minutes.
Fill indent in each cookie with jam or jelly. Enjoy!