Cream butter and sugar. Add egg and beat until well mixed. Gradually add flour and mix until well blended. Add salt and vanilla and mix well. Chill the dough for at least 3 hours before rolling out. Roll out the dough to about ?-inch thickness and cut out cookies. Cut out a hole in the center, leaving at least a ?-inch border. Place cutout cookies on parchment-lined cookie sheets. Fill cutout space with crushed candy. Bake at 350 degrees for 8-10 minutes. Candy should be melted and cookies lightly browned. Let the cookies cool before removing them from the cookie sheet.
An alternative: The dough can also be shaped into logs before chilling and then sliced and decorated with colored sugar or sliced almonds or a few chocolate chips and baked at 350 degrees for 8-10 minutes.
