Preheat the oven to 375F. In a large bowl, with an electric beater on medium speed, cream the butter and confectioners' sugar until light and fluffy. Add the egg and the peppermint and vanilla extracts and beat until well blended. Gradually add the flour and salt; mix well. Cover the bowl tightly with plastic wrap and chill for 1 hour. Coat two baking sheets with nonstick cooking spray. In a shallow bowl, combine the crushed candy canes and the granulated sugar; mix well. Shape the chilled dough into 1-inch balls then roll each ball in the candy cane mixture; place on the baking sheets and bake for 10 to 12 minutes, or until browned. Immediately remove from the baking sheets and place on wire racks to cool.