Chocolate-on-Chocolate Walnut Cookies

In a bowl, combine flour, baking soda, baking powder, and salt; set aside.

In a large mixer bowl, cream sugar and butter on low speed of electric mixer. Add eggs and vanilla; beat on medium speed until fluffy.

Beat in cooled, melted chocolate and sour cream. Add flour mixture; beat on low speed until well-mixed.

With a spoon, stir in black walnuts. Cover; chill for 1 hour.

From a teaspoon, drop dough 2 inches apart onto a greased cookie sheet. Bake in a 375 degree F oven for 8 to 10 minutes. Remove cookies to a wire rack; cool. Frost with Chocolate Cream-Cheese Frosting, if desired. Store frosted cookies in your refrigerator. (Note: Nutrition facts are provided for unfrosted cookies.) Makes about 60 cookies.