Preheat oven to 375 degrees.
Cream butter and sugar in a large mixing bowl.
Add eggs and vanilla and mix, until just combined.
Add salt and baking soda.
Add three cups of flour, one at a time.
Form into dough balls (I love to use my cookie scoop).
Bake for 10 minutes, or until the top of the cookie is slightly brown.
Place candy bar on top of cookie while cookie is still fresh from the oven.