Preheat oven to 375 degrees F (190 degrees C). Grease baking sheet.
In a large bowl, cream together butter and sugar until light and fluffy. Beat in eggs and vanilla. In a separate bowl, combine flour, baking soda, salt, and peppermint extract; gradually add to creamed mixture.
Stir in chocolate chips and walnuts. Drop dough by teaspoonfuls onto prepared baking sheet. Bake for 8 to 10 minutes in preheated oven. Allow cookies to cool on baking sheet for 5 minutes before transferring to a wire rack to cool completely.
Interesting Facts
Thin Mints are a popular Girl Scout cookie.
Chocolate and mint is an iconic flavor combination.
The thin nature of these cookies makes them a great accompaniment to coffee or tea.
These cookies can be stored in an airtight container for up to a week.