Preheat the oven to 180°C/350°F/Gas mark 4
Polos are a well known hard peppermint sweet in England, characterised by a hole in the middle. You can use any type of hard plain mint sweet. You can use spearmint sweets for a variation.
Cream together the butter sugars; beat in the sour cream. Sift together the flour, baking powder and salt; stir into the creamed mixture. Fold in the crushed sweets.
Drop by teaspoonsful onto a greased cookie sheet. Bake at 350 for 10-12 minutes or until cookie edges just begin to brown.
