In a medium size mixing bowl, stir together the flour, baking soda and salt.
In a large mixing bowl, cream together the butter, granulated sugar and brown sugar.
To the creamed sugar mixture, add the eggs and vanilla. Mix with a spoon until well blended.
Slowly add the flour mixture to the creamed mixture, a half cup at a time, mixing thoroughly with a large spoon.
Cover dough with plastic wrap and chill in the refrigerator for two hours.
Preheat oven to 375 degrees Fahrenheit.
Take a teaspoon of dough and roll between the palms of your hands into a ball. Place it on the cookie sheet. Gently press a chocoate wafer down on the ball, flattening the dough and imbedding the wafer.
Roll another teaspoon of dough and place on top of the chocolate wafer. Gently flatten it to completely cover the chocolate wafer. Try to keep the shape of the dough nice and round. These cookies don't 'melt' while cooking, so the shape you make now is the shape your final cookie will have.
Repeat, cookie assembly process, leaving two inches of space between cookies, to fill the cookie sheet.
Place a nut half on top of each cookie and press it lightly to bond it.
Bake 8 to 11 minutes, or until golden brown. Gently transfer cookies to wire racks to cool.