1 cup butter softened
3/4 cup light brown sugar
2 teaspoons vanilla extract
2 cups all-purpose flour
1 tablespoon butter
1 cup chocolate chips (semi-sweet or milk chocolate)

Preheat oven to 325 degrees F.

In a large bowl, cream together butter and sugar until smooth. Add vanilla extract and flour. Shape level teaspoon of dough into log shape and place on cookie sheets 2 inches apart. Bake for 17 to 19 minutes or until golden brown. Cool on cookie sheet 5 minutes and then lay cookies on flat surface to cool. Microwave chocolate chips for 2 minutes and stir in butter. Spread chocolate mixture on one cookie and top with the other cookie.