To make cookies:
1. In a medium bowl, blend butter and brown sugar.
2. Stir in egg, vanilla, baking soda add salt.
3. Gradually stir in flour.
4. Divide dough into 24 portions.
5. Roll into a ball and place 2 inches apart on ungreased baking sheets
6. Using fingertips, make indentation in center of each cookie, leaving ¼ inch rim around the edge.
To make the filling:
1. In a small bowl, stir together brown sugar, sour cream and cinnamon.
2. Stir in walnuts.
3. Spoon filling into center of each cookie.
Bake at 350º for 10-12 minutes in preheated oven. Cool cookies and glaze each cookie.